diff --git a/TODO.md b/TODO.md
index da7d660..890de2b 100644
--- a/TODO.md
+++ b/TODO.md
@@ -13,8 +13,6 @@
 
   - Add RSS/Atom feed construction utilities.
 
-  - Verify structure of the DateTime types.
-
 ## Low Prio
 
   - Get guides working on phpdoc.
diff --git a/VERSION b/VERSION
index 667dcb6..8f4fcc5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.2407.311946
+0.2407.312052
diff --git a/src/Data/Migration/DbMigrationManager.php b/src/Data/Migration/DbMigrationManager.php
index a59c464..412bded 100644
--- a/src/Data/Migration/DbMigrationManager.php
+++ b/src/Data/Migration/DbMigrationManager.php
@@ -1,14 +1,15 @@
 <?php
 // DbMigrationManager.php
 // Created: 2023-01-07
-// Updated: 2023-01-07
+// Updated: 2024-07-31
 
 namespace Index\Data\Migration;
 
 use stdClass;
 use InvalidArgumentException;
+use DateTimeImmutable;
 use DateTimeInterface;
-use Index\DateTime;
+use Index\XDateTime;
 use Index\Data\IDbConnection;
 use Index\Data\IDbStatement;
 use Index\Data\DbType;
@@ -76,7 +77,8 @@ EOF;
     }
 
     public function completeMigration(string $name, ?DateTimeInterface $dateTime = null): void {
-        $dateTime = ($dateTime ?? DateTime::utcNow())->format(DateTimeInterface::ATOM);
+        $dateTime = XDateTime::toISO8601String($dateTime);
+
         $this->insertStmt->reset();
         $this->insertStmt->addParameter(1, $name, DbType::STRING);
         $this->insertStmt->addParameter(2, $dateTime, DbType::STRING);
@@ -88,8 +90,6 @@ EOF;
     }
 
     public function createFileName(string $name, ?DateTimeInterface $dateTime = null): string {
-        $dateTime ??= DateTime::utcNow();
-
         if(empty($name))
             throw new InvalidArgumentException('$name may not be empty.');
 
@@ -97,12 +97,12 @@ EOF;
         if(!preg_match('#^([a-z_]+)$#', $name))
             throw new InvalidArgumentException('$name may only contain alphabetical, spaces and _ characters.');
 
+        $dateTime ??= new DateTimeImmutable('now');
+
         return $dateTime->format('Y_m_d_His_') . trim($name, '_');
     }
 
     public function createClassName(string $name, ?DateTimeInterface $dateTime = null): string {
-        $dateTime ??= DateTime::utcNow();
-
         if(empty($name))
             throw new InvalidArgumentException('$name may not be empty.');
 
@@ -110,6 +110,8 @@ EOF;
         if(!preg_match('#^([a-z_]+)$#', $name))
             throw new InvalidArgumentException('$name may only contain alphabetical, spaces and _ characters.');
 
+        $dateTime ??= new DateTimeImmutable('now');
+
         $parts = explode('_', trim($name, '_'));
         $name = '';
 
@@ -120,7 +122,7 @@ EOF;
     }
 
     public function createNames(string $baseName, ?DateTimeInterface $dateTime = null): object {
-        $dateTime ??= DateTime::utcNow();
+        $dateTime ??= new DateTimeImmutable('now');
 
         $names = new stdClass;
         $names->name = $this->createFileName($baseName, $dateTime);
diff --git a/src/Data/Migration/FsDbMigrationInfo.php b/src/Data/Migration/FsDbMigrationInfo.php
index 21dd6d3..417c661 100644
--- a/src/Data/Migration/FsDbMigrationInfo.php
+++ b/src/Data/Migration/FsDbMigrationInfo.php
@@ -1,11 +1,10 @@
 <?php
 // FsDbMigrationInfo.php
 // Created: 2023-01-07
-// Updated: 2023-01-07
+// Updated: 2024-07-31
 
 namespace Index\Data\Migration;
 
-use DateTime;
 use Index\Data\IDbConnection;
 
 class FsDbMigrationInfo implements IDbMigrationInfo {
diff --git a/src/DateTime.php b/src/DateTime.php
deleted file mode 100644
index cfdda7b..0000000
--- a/src/DateTime.php
+++ /dev/null
@@ -1,659 +0,0 @@
-<?php
-// DateTime.php
-// Created: 2021-06-11
-// Updated: 2024-01-04
-
-namespace Index;
-
-use DateInterval;
-use DateTimeImmutable;
-use DateTimeInterface;
-use DateTimeZone;
-use InvalidArgumentException;
-use JsonSerializable;
-use RuntimeException;
-use Stringable;
-
-/**
- * Represents a date and time
- */
-class DateTime extends DateTimeImmutable implements JsonSerializable, Stringable, IComparable, IEquatable {
-    /**
-     * Represents Sunday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const SUNDAY = 0;
-
-    /**
-     * Represents Monday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const MONDAY = 1;
-
-    /**
-     * Represents Tuesday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const TUESDAY = 2;
-
-    /**
-     * Represents Wednesday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const WEDNESDAY = 3;
-
-    /**
-     * Represents Thursday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const THURSDAY = 4;
-
-    /**
-     * Represents Friday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const FRIDAY = 5;
-
-    /**
-     * Represents Saturday for getDayOfWeek.
-     *
-     * @var int
-     */
-    public const SATURDAY = 6;
-
-    private const COMPARE = 'YmdHisu';
-
-    /**
-     * Creates a new DateTime object.
-     *
-     * @see https://www.php.net/manual/en/datetime.formats.php
-     * @param string $dateTime A date/time string.
-     * @param DateTimeZone|null $timeZone An object representing the desired time zone.
-     * @return DateTime A new DateTime instance.
-     */
-    public function __construct(string $dateTime = 'now', DateTimeZone|null $timeZone = null) {
-        parent::__construct($dateTime, $timeZone);
-    }
-
-    /**
-     * Gets the date component of this instance.
-     *
-     * @return DateTime New instance with the same date but the time set to 00:00:00.
-     */
-    public function getDate(): DateTime {
-        return self::create($this->getYear(), $this->getMonth(), $this->getDay(), 0, 0, 0, 0, $this->getTimezone());
-    }
-
-    /**
-     * Gets the year component of this instance.
-     *
-     * @return int Year component.
-     */
-    public function getYear(): int {
-        return (int)$this->format('Y');
-    }
-
-    /**
-     * Gets the month component of this instance.
-     *
-     * @return int Month component, ranging from 1 to 12.
-     */
-    public function getMonth(): int {
-        return (int)$this->format('n');
-    }
-
-    /**
-     * Gets the day component of this instance.
-     *
-     * @return int Day component, ranging from 1 to 31.
-     */
-    public function getDay(): int {
-        return (int)$this->format('j');
-    }
-
-    /**
-     * Gets the day of the week represented by this instance.
-     *
-     * See the SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY and SATURDAY constants for the possible return values of this function.
-     *
-     * @return int Integer between 0 and 6 representing the day of the week.
-     */
-    public function getDayOfWeek(): int {
-        return (int)$this->format('w');
-    }
-
-    /**
-     * Gets the day of the year represented by this instance.
-     *
-     * @return int Day of the year, ranging from 1-366.
-     */
-    public function getDayOfYear(): int {
-        return ((int)$this->format('z')) + 1;
-    }
-
-    /**
-     * Gets the ISO8601 week number of this instance.
-     *
-     * @return int Integer representing the current week number.
-     */
-    public function getWeek(): int {
-        return (int)$this->format('W');
-    }
-
-    /**
-     * Gets the time of day for this instance.
-     *
-     * @return TimeSpan A TimeSpan representing the amount of time elapsed since midnight.
-     */
-    public function getTimeOfDay(): TimeSpan {
-        return TimeSpan::create(0, $this->getHour(), $this->getMinute(), $this->getSecond(), $this->getMicrosecond());
-    }
-
-    /**
-     * Gets the hour component of this instance.
-     *
-     * @return int Hour component, ranging from 0 to 23.
-     */
-    public function getHour(): int {
-        return (int)$this->format('G');
-    }
-
-    /**
-     * Gets the minute component of this instance.
-     *
-     * @return int Minute component, ranging from 0 to 59.
-     */
-    public function getMinute(): int {
-        return (int)$this->format('i');
-    }
-
-    /**
-     * Gets the second component of this instance.
-     *
-     * @return int Second component, ranging from 0 to 59.
-     */
-    public function getSecond(): int {
-        return (int)$this->format('s');
-    }
-
-    /**
-     * Gets the millisecond component of this instance.
-     *
-     * @return int Millisecond component, ranging from 0 to 999.
-     */
-    public function getMillisecond(): int {
-        return (int)$this->format('v');
-    }
-
-    /**
-     * Gets the microsecond component of this instance.
-     *
-     * @return int Microsecond component, ranging from 0 to 999999.
-     */
-    public function getMicrosecond(): int {
-        return (int)$this->format('u');
-    }
-
-    /**
-     * Gets the number of seconds that have elapsed since midnight January 1st, 1970 UTC for this instance.
-     *
-     * @return int Number of seconds.
-     */
-    public function getUnixTimeSeconds(): int {
-        return (int)$this->format('U');
-    }
-
-    /**
-     * Gets the number of milliseconds that have elapsed since midnight January 1st, 1970 UTC for this instance.
-     *
-     * @return float Number of milliseconds.
-     */
-    public function getUnixTimeMilliseconds(): float {
-        return (float)$this->format('Uv');
-    }
-
-    /**
-     * Gets whether Daylight Savings is in effect during the time this instance represents.
-     *
-     * @return bool true if DST is in effect, false if not.
-     */
-    public function isDaylightSavingTime(): bool {
-        return $this->format('I') !== '0';
-    }
-
-    /**
-     * Gets whether the year this instance represents is a leap year.
-     *
-     * @return bool true if the year is a leap year, false if not.
-     */
-    public function isLeapYear(): bool {
-        return $this->format('L') !== '0';
-    }
-
-    /**
-     * Gets whether this DateTime uses UTC date/time.
-     *
-     * @return bool true if UTC, false if not.
-     */
-    public function isUTC(): bool {
-        return $this->getTimezone()->equals(TimeZoneInfo::utc());
-    }
-
-    /**
-     * Gets the time zone for this instance.
-     *
-     * @return TimeZoneInfo Time zone for this instance.
-     */
-    public function getTimezone(): TimeZoneInfo {
-        return TimeZoneInfo::cast(parent::getTimezone());
-    }
-
-    /**
-     * Adds a period of time to this date time object.
-     *
-     * @param DateInterval $timeSpan Time period to add to this DateTime.
-     * @return DateTime A DateTime instance which is the sum of this instance and the provided period.
-     */
-    public function add(DateInterval $timeSpan): DateTime {
-        return self::cast(parent::add($timeSpan));
-    }
-
-    /**
-     * Adds a number of years to this instance.
-     *
-     * @param float $years Number of years to add.
-     * @return DateTime New DateTime instance with the years added.
-     */
-    public function addYears(float $years): DateTime {
-        return $this->add(TimeSpan::fromDays(365 * $years));
-    }
-
-    /**
-     * Adds a number of months to this instance.
-     *
-     * @param float $months Number of months to add.
-     * @return DateTime New DateTime instance with the months added.
-     */
-    public function addMonths(float $months): DateTime {
-        return $this->add(TimeSpan::fromDays(365 * 31 * $months));
-    }
-
-    /**
-     * Adds a number of days to this instance.
-     *
-     * @param float $days Number of days to add.
-     * @return DateTime New DateTime instance with the days added.
-     */
-    public function addDays(float $days): DateTime {
-        return $this->add(TimeSpan::fromDays($days));
-    }
-
-    /**
-     * Adds a number of hours to this instance.
-     *
-     * @param float $hours Number of hours to add.
-     * @return DateTime New DateTime instance with the hours added.
-     */
-    public function addHours(float $hours): DateTime {
-        return $this->add(TimeSpan::fromHours($hours));
-    }
-
-    /**
-     * Adds a number of minutes to this instance.
-     *
-     * @param float $minutes Number of minutes to add.
-     * @return DateTime New DateTime instance with the minutes added.
-     */
-    public function addMinutes(float $minutes): DateTime {
-        return $this->add(TimeSpan::fromMinutes($minutes));
-    }
-
-    /**
-     * Adds a number of seconds to this instance.
-     *
-     * @param float $seconds Number of seconds to add.
-     * @return DateTime New DateTime instance with the seconds added.
-     */
-    public function addSeconds(float $seconds): DateTime {
-        return $this->add(TimeSpan::fromSeconds($seconds));
-    }
-
-    /**
-     * Adds a number of milliseconds to this instance.
-     *
-     * @param float $millis Number of milliseconds to add.
-     * @return DateTime New DateTime instance with the milliseconds added.
-     */
-    public function addMilliseconds(float $millis): DateTime {
-        return $this->add(TimeSpan::fromMilliseconds($millis));
-    }
-
-    /**
-     * Adds a number of microseconds to this instance.
-     *
-     * @param float $micros Number of microseconds to add.
-     * @return DateTime New DateTime instance with the microseconds added.
-     */
-    public function addMicroseconds(float $micros): DateTime {
-        return $this->add(TimeSpan::fromMicroseconds($micros));
-    }
-
-    /**
-     * Subtracts a time period from this DateTime.
-     *
-     * @param DateInterval $timeSpan Time period to be subtracted.
-     * @return DateTime A new DateTime instance which is this instance minus the given time period.
-     */
-    public function subtract(DateInterval $timeSpan): DateTime {
-        return self::cast(parent::sub($timeSpan));
-    }
-
-    /**
-     * Alias for difference, must exist because of the DateTimeImmutable inheritance but I don't like short names.
-     *
-     * @internal
-     */
-    public function diff(DateTimeInterface $dateTime, bool $absolute = false): TimeSpan {
-        return $this->difference($dateTime, $absolute);
-    }
-
-    /**
-     * Subtracts another Date/Time from this DateTime.
-     *
-     * @param DateTimeInterface $dateTime Date/time to subtract.
-     * @return TimeSpan Difference between this DateTime and the provided one.
-     */
-    public function difference(DateTimeInterface $dateTime, bool $absolute = false): TimeSpan {
-        return TimeSpan::cast(parent::diff($dateTime, $absolute));
-    }
-
-    /**
-     * Applies a modifier on this instance and returns the result as a new instance.
-     *
-     * @see https://www.php.net/manual/en/datetime.formats.php
-     * @param string $modifier A date/time format.
-     * @return DateTime The modified date/time.
-     */
-    public function modify(string $modifier): DateTime {
-        return self::cast(parent::modify($modifier));
-    }
-
-    /**
-     * Creates a new DateTime with the given date component.
-     *
-     * @param int $year Desired year component.
-     * @param int $month Desired month component.
-     * @param int $day Desired day component.
-     * @return DateTime A new DateTime instance with the given date component.
-     */
-    public function setDate(int $year, int $month, int $day): DateTime {
-        return self::cast(parent::setDate($year, $month, $day));
-    }
-
-    /**
-     * Creates a new DateTime with the given ISO date for the date component.
-     *
-     * @param int $year Year of the date.
-     * @param int $week Week of the date.
-     * @param int $dayOfWeek Offset from the first of the week.
-     * @return DateTime A new DateTime instance with the given date component.
-     */
-    public function setISODate(int $year, int $week, int $dayOfWeek = 1): DateTime {
-        return self::cast(parent::setISODate($year, $week, $dayOfWeek));
-    }
-
-    /**
-     * Creates a new DateTime with the given time component.
-     *
-     * @param int $hour Desired hour component.
-     * @param int $minute Desired minute component.
-     * @param int $second Desired second component.
-     * @param int $microsecond Desired microsecond component.
-     * @return DateTime A new DateTime instance with the given time component.
-     */
-    public function setTime(int $hour, int $minute, int $second = 0, int $microsecond = 0): DateTime {
-        return self::cast(parent::setTime($hour, $minute, $second, $microsecond));
-    }
-
-    /**
-     * Creates a new DateTime with the date and time components based on a Unix timestamp.
-     *
-     * @param int $timestamp Unix timestamp representing the date.
-     * @return DateTime A new DateTime instance with the given date and time.
-     */
-    public function setTimestamp(int $timestamp): DateTime {
-        return self::cast(parent::setTimestamp($timestamp));
-    }
-
-    /**
-     * Creates a new DateTime with the given time zone.
-     *
-     * @param DateTimeZone $timeZone An object representing the desired time zone.
-     * @return DateTime A new DateTime with the given time zone.
-     */
-    public function setTimezone(DateTimeZone $timeZone): DateTime {
-        return self::cast(parent::setTimezone($timeZone));
-    }
-
-    public function compare(mixed $other): int {
-        if($other instanceof DateTimeInterface)
-            return strcmp($this->format(self::COMPARE), $other->format(self::COMPARE));
-        return -1;
-    }
-
-    public function equals(mixed $other): bool {
-        if($other instanceof DateTimeInterface)
-            return $this->format(self::COMPARE) === $other->format(self::COMPARE);
-        return false;
-    }
-
-    public function isLessThan(DateTimeInterface $other): bool {
-        return $this->compare($other) < 0;
-    }
-
-    public function isLessThanOrEqual(DateTimeInterface $other): bool {
-        return $this->compare($other) <= 0;
-    }
-
-    public function isMoreThan(DateTimeInterface $other): bool {
-        return $this->compare($other) > 0;
-    }
-
-    public function isMoreThanOrEqual(DateTimeInterface $other): bool {
-        return $this->compare($other) >= 0;
-    }
-
-    /**
-     * Formats this DateTime as an ISO8601 date/time string.
-     *
-     * @return string This object represented as an ISO8601 date/time string.
-     */
-    public function toISO8601String(): string {
-        return $this->format(DateTimeInterface::ATOM);
-    }
-
-    /**
-     * Formats this DateTime as a Cookie date/time string.
-     *
-     * @return string This object represented as a Cookie date/time string.
-     */
-    public function toCookieString(): string {
-        return $this->format(DateTimeInterface::COOKIE);
-    }
-
-    /**
-     * Formats this DateTime as an RFC 822 date/time string.
-     *
-     * @return string This object represented as an RFC 822 date/time string.
-     */
-    public function toRFC822String(): string {
-        return $this->format(DateTimeInterface::RFC822);
-    }
-
-    /**
-     * Creates a string representation of this object.
-     *
-     * @return string Representation of this object.
-     */
-    public function __toString(): string {
-        return $this->format(DateTimeInterface::ATOM);
-    }
-
-    /**
-     * Returns the data which should be serialized as json.
-     *
-     * @see https://www.php.net/manual/en/jsonserializable.jsonserialize.php
-     * @return mixed Data to be passed to json_encode.
-     */
-    public function jsonSerialize(): mixed {
-        return (string)$this;
-    }
-
-    /**
-     * Converts this immutable \Index\DateTime type to a mutable \DateTime type.
-     *
-     * @return \DateTime A new mutable \DateTime instance.
-     */
-    public function toNative(): \DateTime {
-        return \DateTime::createFromImmutable($this);
-    }
-
-    /**
-     * Creates a DateTime object that is set to the current date and time, expressed in the provided time zone.
-     *
-     * @param DateTimeZone $timeZone Desired time zone, null for the current default time zone.
-     * @return DateTime An instance representing now.
-     */
-    public static function now(?DateTimeZone $timeZone = null): DateTime {
-        return new DateTime('now', $timeZone);
-    }
-
-    /**
-     * Creates a DateTime object that is set to the current date and time, expressed in UTC.
-     *
-     * @return DateTime An instance representing now in UTC.
-     */
-    public static function utcNow(): DateTime {
-        return self::now(TimeZoneInfo::utc());
-    }
-
-    /**
-     * Converts Unix time seconds to a DateTime object.
-     *
-     * @param int $seconds Unix time seconds.
-     * @return DateTime A DateTime instance representing the Unix time.
-     */
-    public static function fromUnixTimeSeconds(int $seconds): DateTime {
-        return new DateTime('@' . $seconds);
-    }
-
-    /**
-     * Converts Unix time milliseconds to a DateTime object.
-     *
-     * @param float $millis Unix time milliseconds.
-     * @return DateTime A DateTime instance representing the Unix time.
-     */
-    public static function fromUnixTimeMilliseconds(float $millis): DateTime {
-        return new DateTime('@' . ($millis / 1000));
-    }
-
-    /**
-     * Creates a new DateTime instance with the given components.
-     *
-     * @param int $year Desired year component.
-     * @param int $month Desired month component.
-     * @param int $day Desired day component.
-     * @param int $hour Desired hour component.
-     * @param int $minute Desired minute component.
-     * @param int $second Desired second component.
-     * @param int $micros Desired microsecond component.
-     * @param ?DateTimeZone $timeZone Desired time zone.
-     */
-    public static function create(int $year, int $month = 1, int $day = 1, int $hour = 0, int $minute = 0, int $second = 0, int $micros = 0, ?DateTimeZone $timeZone = null): DateTime {
-        if($year < 1 || $year > 9999)
-            throw new InvalidArgumentException('$year may not be less than 1 or more than 9999.');
-        if($month < 1 || $month > 12)
-            throw new InvalidArgumentException('$month may not be less than 1 or more than 12.');
-        if($day < 1 || $day > 31)
-            throw new InvalidArgumentException('$day may not be less than 1 or more than 31.');
-        if($hour < 0 || $hour > 23)
-            throw new InvalidArgumentException('$hour may not be less than 0 or more than 23.');
-        if($minute < 0 || $minute > 59)
-            throw new InvalidArgumentException('$minute may not be less than 0 or more than 59.');
-        if($second < 0 || $second > 59)
-            throw new InvalidArgumentException('$second may not be less than 0 or more than 59.');
-        if($micros < 0 || $micros > 999999)
-            throw new InvalidArgumentException('$micros may not be less than 0 or more than 999999.');
-
-        return new DateTime(
-            sprintf(
-                '%04d-%02d-%02dT%02d:%02d:%02d.%06d',
-                $year, $month, $day, $hour, $minute, $second, $micros
-            ),
-            $timeZone
-        );
-    }
-
-    /**
-     * Parses a time string and creates a DateTime using it.
-     *
-     * @see https://www.php.net/manual/en/datetime.createfromformat
-     * @param string $format Format that the passed string should be in.
-     * @param string $dateTime String representing the time.
-     * @param ?DateTimeZone $timeZone Desired time zone.
-     * @return DateTime|false A DateTime instance, or false on failure.
-     */
-    public static function createFromFormat(string $format, string $dateTime, ?DateTimeZone $timeZone = null): DateTime|false {
-        $instance = parent::createFromFormat($format, $dateTime, $timeZone);
-        if($instance === false)
-            return false;
-        return self::cast($instance);
-    }
-
-    /**
-     * Creates a new DateTime instance from an interface implementation.
-     *
-     * @param DateTimeInterface $object Object that should be sourced.
-     * @return DateTime A new DateTime instance.
-     */
-    public static function createFromInterface(DateTimeInterface $object): DateTime {
-        return self::cast($object);
-    }
-
-    /**
-     * Creates a new immutable DateTime instance from a mutable instance.
-     *
-     * @param \DateTime $object Mutable object that should be sourced.
-     * @return DateTime New immutable DateTime representing the same value.
-     */
-    #[\ReturnTypeWillChange]
-    public static function createFromMutable(\DateTime $object): DateTime {
-        return self::cast($object);
-    }
-
-    /**
-     * @internal
-     */
-    public static function __set_state(array $array): DateTime {
-        return self::cast(parent::__set_state($array));
-    }
-
-    /**
-     * Makes sure a DateTimeInterface implementing object is a DateTime instance.
-     *
-     * @param DateTimeInterface $dateTime Input object.
-     * @return DateTime If the input was a DateTime, the same instance will be returned.
-     *                  If the input was something else, a new DateTime instance will be returned based on the input.
-     */
-    public static function cast(DateTimeInterface $dateTime): DateTime {
-        if($dateTime instanceof DateTime)
-            return $dateTime;
-        return new DateTime($dateTime->format('@U.u'), $dateTime->getTimezone());
-    }
-}
diff --git a/src/Http/Headers/DateHeader.php b/src/Http/Headers/DateHeader.php
index 31f347f..bfe4bc4 100644
--- a/src/Http/Headers/DateHeader.php
+++ b/src/Http/Headers/DateHeader.php
@@ -1,25 +1,31 @@
 <?php
 // DateHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-14
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
-use Index\DateTime;
+use DateTimeImmutable;
+use DateTimeInterface;
+use RuntimeException;
 use Index\Http\HttpHeader;
 
 class DateHeader {
-    private DateTime $dateTime;
+    private DateTimeImmutable $dateTime;
 
-    public function __construct(DateTime $dateTime) {
+    public function __construct(DateTimeImmutable $dateTime) {
         $this->dateTime = $dateTime;
     }
 
-    public function getDateTime(): DateTime {
+    public function getDateTime(): DateTimeImmutable {
         return $this->dateTime;
     }
 
     public static function parse(HttpHeader $header): DateHeader {
-        return new DateHeader(DateTime::createFromFormat(\DateTimeInterface::RFC7231, $header->getFirstLine()));
+        $parsed = DateTimeImmutable::createFromFormat(DateTimeInterface::RFC7231, $header->getFirstLine());
+        if($parsed === false)
+            throw new RuntimeException('Failed to parse Date header.');
+
+        return new DateHeader($parsed);
     }
 }
diff --git a/src/Http/Headers/IfModifiedSinceHeader.php b/src/Http/Headers/IfModifiedSinceHeader.php
index 94224e3..3e0d0fe 100644
--- a/src/Http/Headers/IfModifiedSinceHeader.php
+++ b/src/Http/Headers/IfModifiedSinceHeader.php
@@ -1,30 +1,36 @@
 <?php
 // IfModifiedSinceHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-14
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
+use DateTimeImmutable;
 use DateTimeInterface;
-use Index\DateTime;
+use RuntimeException;
+use Index\XDateTime;
 use Index\Http\HttpHeader;
 
 class IfModifiedSinceHeader {
-    private DateTime $dateTime;
+    private DateTimeImmutable $dateTime;
 
-    public function __construct(DateTime $dateTime) {
+    public function __construct(DateTimeImmutable $dateTime) {
         $this->dateTime = $dateTime;
     }
 
-    public function getDateTime(): DateTime {
+    public function getDateTime(): DateTimeImmutable {
         return $this->dateTime;
     }
 
-    public function isLessThanOrEqual(DateTimeInterface $dateTime): bool {
-        return $this->dateTime->isLessThanOrEqual($dateTime);
+    public function isLessThanOrEqual(DateTimeInterface $other): bool {
+        return XDateTime::compare($this->dateTime, $other) <= 0;
     }
 
     public static function parse(HttpHeader $header): IfModifiedSinceHeader {
-        return new IfModifiedSinceHeader(DateTime::createFromFormat(\DateTimeInterface::RFC7231, $header->getFirstLine()));
+        $parsed = DateTimeImmutable::createFromFormat(DateTimeInterface::RFC7231, $header->getFirstLine());
+        if($parsed === false)
+            throw new RuntimeException('Failed to parse If-Modified-Since header.');
+
+        return new IfModifiedSinceHeader($parsed);
     }
 }
diff --git a/src/Http/Headers/IfRangeHeader.php b/src/Http/Headers/IfRangeHeader.php
index 17051f6..74c3edf 100644
--- a/src/Http/Headers/IfRangeHeader.php
+++ b/src/Http/Headers/IfRangeHeader.php
@@ -1,19 +1,21 @@
 <?php
 // IfRangeHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-27
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
+use DateTimeImmutable;
 use DateTimeInterface;
-use Index\DateTime;
+use RuntimeException;
+use Index\XDateTime;
 use Index\Http\HttpHeader;
 
 class IfRangeHeader {
     private ?string $tag;
-    private ?DateTime $dateTime;
+    private ?DateTimeImmutable $dateTime;
 
-    public function __construct(?string $tag, ?DateTime $dateTime) {
+    public function __construct(?string $tag, ?DateTimeImmutable $dateTime) {
         $this->tag = $tag;
         $this->dateTime = $dateTime;
     }
@@ -30,7 +32,7 @@ class IfRangeHeader {
         return $this->dateTime !== null;
     }
 
-    public function getDateTime(): DateTime {
+    public function getDateTime(): DateTimeImmutable {
         return $this->dateTime;
     }
 
@@ -42,7 +44,7 @@ class IfRangeHeader {
         }
 
         if($this->hasDateTime() && $other instanceof DateTimeInterface)
-            return $this->dateTime->isLessThanOrEqual($other);
+            return XDateTime::compare($this->dateTime, $other) <= 0;
 
         return false;
     }
@@ -50,8 +52,13 @@ class IfRangeHeader {
     public static function parse(HttpHeader $header): IfRangeHeader {
         $line = $header->getFirstLine();
 
-        if($line[0] !== '"' && !str_starts_with($line, 'W/"'))
-            return new IfRangeHeader(null, DateTime::createFromFormat(\DateTimeInterface::RFC7231, $line));
+        if($line[0] !== '"' && !str_starts_with($line, 'W/"')) {
+            $parsed = DateTimeImmutable::createFromFormat(DateTimeInterface::RFC7231, $line);
+            if($parsed === false)
+                throw new RuntimeException('Failed to parse If-Range header.');
+
+            return new IfRangeHeader(null, $parsed);
+        }
 
         return new IfRangeHeader($line, null);
     }
diff --git a/src/Http/Headers/IfUnmodifiedSinceHeader.php b/src/Http/Headers/IfUnmodifiedSinceHeader.php
index 92245a5..86e4937 100644
--- a/src/Http/Headers/IfUnmodifiedSinceHeader.php
+++ b/src/Http/Headers/IfUnmodifiedSinceHeader.php
@@ -1,30 +1,36 @@
 <?php
 // IfUnmodifiedSinceHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-14
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
+use DateTimeImmutable;
 use DateTimeInterface;
-use Index\DateTime;
+use RuntimeException;
+use Index\XDateTime;
 use Index\Http\HttpHeader;
 
 class IfUnmodifiedSinceHeader {
-    private DateTime $dateTime;
+    private DateTimeImmutable $dateTime;
 
-    public function __construct(DateTime $dateTime) {
+    public function __construct(DateTimeImmutable $dateTime) {
         $this->dateTime = $dateTime;
     }
 
-    public function getDateTime(): DateTime {
+    public function getDateTime(): DateTimeImmutable {
         return $this->dateTime;
     }
 
-    public function isMoreThan(DateTimeInterface $dateTime): bool {
-        return $this->dateTime->isMoreThan($dateTime);
+    public function isMoreThan(DateTimeInterface $other): bool {
+        return XDateTime::compare($this->dateTime, $other) > 0;
     }
 
     public static function parse(HttpHeader $header): IfUnmodifiedSinceHeader {
-        return new IfUnmodifiedSinceHeader(DateTime::createFromFormat(\DateTimeInterface::RFC7231, $header->getFirstLine()));
+        $parsed = DateTimeImmutable::createFromFormat(DateTimeInterface::RFC7231, $header->getFirstLine());
+        if($parsed === false)
+            throw new RuntimeException('Failed to parse If-Unmodified-Since header.');
+
+        return new IfUnmodifiedSinceHeader($parsed);
     }
 }
diff --git a/src/Http/Headers/LastModifiedHeader.php b/src/Http/Headers/LastModifiedHeader.php
index 4874fce..b4916c9 100644
--- a/src/Http/Headers/LastModifiedHeader.php
+++ b/src/Http/Headers/LastModifiedHeader.php
@@ -1,25 +1,31 @@
 <?php
 // LastModifiedHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-14
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
-use Index\DateTime;
+use DateTimeImmutable;
+use DateTimeInterface;
+use RuntimeException;
 use Index\Http\HttpHeader;
 
 class LastModifiedHeader {
-    private DateTime $dateTime;
+    private DateTimeImmutable $dateTime;
 
-    public function __construct(DateTime $dateTime) {
+    public function __construct(DateTimeImmutable $dateTime) {
         $this->dateTime = $dateTime;
     }
 
-    public function getDateTime(): DateTime {
+    public function getDateTime(): DateTimeImmutable {
         return $this->dateTime;
     }
 
     public static function parse(HttpHeader $header): LastModifiedHeader {
-        return new LastModifiedHeader(DateTime::createFromFormat(\DateTimeInterface::RFC7231, $header->getFirstLine()));
+        $parsed = DateTimeImmutable::createFromFormat(DateTimeInterface::RFC7231, $header->getFirstLine());
+        if($parsed === false)
+            throw new RuntimeException('Failed to parse Last-Modified header.');
+
+        return new LastModifiedHeader($parsed);
     }
 }
diff --git a/src/Http/Headers/OriginHeader.php b/src/Http/Headers/OriginHeader.php
index 601e27f..d925ac4 100644
--- a/src/Http/Headers/OriginHeader.php
+++ b/src/Http/Headers/OriginHeader.php
@@ -1,11 +1,10 @@
 <?php
 // OriginHeader.php
 // Created: 2022-02-14
-// Updated: 2022-02-27
+// Updated: 2024-07-31
 
 namespace Index\Http\Headers;
 
-use Index\DateTime;
 use Index\Http\HttpHeader;
 
 class OriginHeader {
diff --git a/src/Http/HttpResponseBuilder.php b/src/Http/HttpResponseBuilder.php
index 0509707..f9d99c4 100644
--- a/src/Http/HttpResponseBuilder.php
+++ b/src/Http/HttpResponseBuilder.php
@@ -1,14 +1,14 @@
 <?php
 // HttpResponseBuilder.php
 // Created: 2022-02-08
-// Updated: 2023-01-10
+// Updated: 2024-07-31
 
 namespace Index\Http;
 
 use DateTimeInterface;
-use Index\DateTime;
 use Index\UrlEncoding;
 use Index\MediaType;
+use Index\XDateTime;
 use Index\Performance\Timings;
 
 class HttpResponseBuilder extends HttpMessageBuilder {
@@ -53,16 +53,8 @@ class HttpResponseBuilder extends HttpMessageBuilder {
         $cookie = rawurlencode($name) . '=' . rawurlencode($value)
             . '; SameSite=' . ($sameSiteStrict ? 'Strict' : 'Lax');
 
-        if($expires !== null) {
-            if(!($expires instanceof DateTime)) {
-                if(is_int($expires))
-                    $expires = DateTime::fromUnixTimeSeconds($expires);
-                else
-                    $expires = DateTime::createFromInterface($expires);
-            }
-
-            $cookie .= '; Expires=' . $expires->toCookieString();
-        }
+        if($expires !== null)
+            $cookie .= '; Expires=' . XDateTime::toCookieString($expires);
 
         if(!empty($domain))
             $cookie .= '; Domain=' . $domain;
diff --git a/src/TimeSpan.php b/src/TimeSpan.php
deleted file mode 100644
index 83b6648..0000000
--- a/src/TimeSpan.php
+++ /dev/null
@@ -1,526 +0,0 @@
-<?php
-// TimeSpan.php
-// Created: 2021-06-11
-// Updated: 2022-02-27
-
-namespace Index;
-
-use DateInterval;
-use JsonSerializable;
-use Stringable;
-
-/**
- * Represents a duration of time.
- */
-class TimeSpan extends DateInterval implements JsonSerializable, Stringable, IComparable, IEquatable {
-    private const HOURS_IN_DAY = 24;
-    private const MINS_IN_HOUR = 60;
-    private const SECS_IN_MIN = 60;
-    private const MILLIS_IN_SEC = 1000;
-    private const MINS_IN_DAY = 1440;
-    private const SECS_IN_HOUR = 3600;
-    private const MILLIS_IN_MIN = 60000;
-    private const SECS_IN_DAY = 86400;
-    private const MICROS_IN_SEC = 1000000;
-    private const MILLIS_IN_HOUR = 3600000;
-    private const MICROS_IN_MIN = 60000000;
-    private const MILLIS_IN_DAY = 86400000;
-    private const MICROS_IN_HOUR = 3600000000;
-    private const MICROS_IN_DAY = 86400000000;
-
-    private int $realDays = -1;
-
-    /**
-     * Creates a new instance of TimeSpan.
-     *
-     * @param string $duration An ISO8601 duration string.
-     * @return TimeSpan A TimeSpan instance representing the given duration.
-     */
-    public function __construct(string $duration = 'PT0S') {
-        parent::__construct($duration);
-        $this->realDays = $this->days === false ? $this->calculateRealDays() : $this->days;
-    }
-
-    private function calculateRealDays(): int {
-        return ($this->y * 365)
-             + ($this->m * 31)
-             +  $this->d;
-    }
-
-    /**
-     * Gets the amount of days this TimeSpan represents.
-     *
-     * @return int Amount of days.
-     */
-    public function getDays(): int {
-        return $this->realDays;
-    }
-
-    /**
-     * Gets the amount of hours this TimeSpan represents.
-     *
-     * @retunr int Amount of hours.
-     */
-    public function getHours(): int {
-        return $this->h;
-    }
-
-    /**
-     * Gets the amount of minutes this TimeSpan represents.
-     *
-     * @return int Amount of minutes.
-     */
-    public function getMinutes(): int {
-        return $this->i;
-    }
-
-    /**
-     * Gets the amount of seconds this TimeSpan represents.
-     *
-     * @return int Amount of seconds.
-     */
-    public function getSeconds(): int {
-        return $this->s;
-    }
-
-    /**
-     * Gets the amount of milliseconds this TimeSpan represents.
-     *
-     * @return int Amount of milliseconds.
-     */
-    public function getMilliseconds(): int {
-        return (int)($this->f * 1000);
-    }
-
-    /**
-     * Gets the amount of microseconds this TimeSpan represents.
-     *
-     * @return int Amount of microseconds.
-     */
-    public function getMicroseconds(): int {
-        return (int)($this->f * 1000000);
-    }
-
-    /**
-     * Gets whether this TimeSpan represents a negative amount of time.
-     *
-     * @return bool true if negative, false if positive.
-     */
-    public function isNegative(): bool {
-        return $this->invert !== 0;
-    }
-
-    /**
-     * Counts the total amount of days this TimeSpan contains.
-     *
-     * @return float Total amount of days.
-     */
-    public function totalDays(): float {
-        $days  = $this->getDays();
-        $days += $this->getHours() / self::HOURS_IN_DAY;
-        $days += $this->getMinutes() / self::MINS_IN_DAY;
-        $days += $this->getSeconds() / self::SECS_IN_DAY;
-        $days += $this->getMicroseconds() / self::MICROS_IN_DAY;
-        return $days;
-    }
-
-    /**
-     * Counts the total amount of hours this TimeSpan contains.
-     *
-     * @return float Total amount of hours.
-     */
-    public function totalHours(): float {
-        $hours  = $this->getDays() * self::HOURS_IN_DAY;
-        $hours += $this->getHours();
-        $hours += $this->getMinutes() / self::MINS_IN_HOUR;
-        $hours += $this->getSeconds() / self::SECS_IN_HOUR;
-        $hours += $this->getMicroseconds() / self::MICROS_IN_HOUR;
-        return $hours;
-    }
-
-    /**
-     * Counts the total amount of minutes this TimeSpan contains.
-     *
-     * @return float Total amount of minutes.
-     */
-    public function totalMinutes(): float {
-        $mins  = $this->getDays() * self::MINS_IN_DAY;
-        $mins += $this->getHours() * self::MINS_IN_HOUR;
-        $mins += $this->getMinutes();
-        $mins += $this->getSeconds() / self::SECS_IN_MIN;
-        $mins += $this->getMicroseconds() / self::MICROS_IN_MIN;
-        return $mins;
-    }
-
-    /**
-     * Counts the total amount of seconds this TimeSpan contains.
-     *
-     * @return float Total amount of seconds.
-     */
-    public function totalSeconds(): float {
-        $secs  = $this->getDays() * self::SECS_IN_DAY;
-        $secs += $this->getHours() * self::SECS_IN_HOUR;
-        $secs += $this->getMinutes() * self::SECS_IN_MIN;
-        $secs += $this->getSeconds();
-        $secs += $this->getMicroseconds() * self::MICROS_IN_SEC;
-        return $secs;
-    }
-
-    /**
-     * Counts the total amount of milliseconds this TimeSpan contains.
-     *
-     * @return float Total amount of milliseconds.
-     */
-    public function totalMilliseconds(): float {
-        $millis  = $this->getDays() * self::MILLIS_IN_DAY;
-        $millis += $this->getHours() * self::MILLIS_IN_HOUR;
-        $millis += $this->getMinutes() * self::MILLIS_IN_MIN;
-        $millis += $this->getSeconds() * self::MILLIS_IN_SEC;
-        $millis += $this->getMilliseconds();
-        return $millis;
-    }
-
-    /**
-     * Counts the total amount of microseconds this TimeSpan contains.
-     *
-     * @return float Total amount of microseconds.
-     */
-    public function totalMicroseconds(): float {
-        $micros  = $this->getDays() * self::MICROS_IN_DAY;
-        $micros += $this->getHours() * self::MICROS_IN_HOUR;
-        $micros += $this->getMinutes() * self::MICROS_IN_MIN;
-        $micros += $this->getSeconds() * self::MICROS_IN_SEC;
-        $micros += $this->getMicroseconds();
-        return $micros;
-    }
-
-    /**
-     * Returns a new TimeSpan whose value is the sum of this instance and the provided instance.
-     *
-     * @param DateInterval $timeSpan Interval to add.
-     * @return TimeSpan Instance that represents this instance plus the value of $timeSpan.
-     */
-    public function add(DateInterval $timeSpan): TimeSpan {
-        $timeSpan = self::cast($timeSpan);
-
-        $days1 = $this->totalDays();
-        if($this->isNegative())
-            $days1 *= -1;
-
-        $days2 = $timeSpan->totalDays();
-        if($timeSpan->isNegative())
-            $days2 *= -1;
-
-        return self::fromDays($days1 + $days2);
-    }
-
-    /**
-     * Returns a new TimeSpan whose value is the difference of this instance and the provided instance.
-     *
-     * @param DateInterval $timeSpan Interval to subtract.
-     * @return TimeSpan Instance that represents this instance minus the value of $timeSpan.
-     */
-    public function subtract(DateInterval $timeSpan): TimeSpan {
-        $timeSpan = self::cast($timeSpan);
-
-        $days1 = $this->totalDays();
-        if($this->isNegative())
-            $days1 *= -1;
-
-        $days2 = $timeSpan->totalDays();
-        if($timeSpan->isNegative())
-            $days2 *= -1;
-
-        return self::fromDays($days1 - $days2);
-    }
-
-    /**
-     * Returns the result of a division of this instance and the provided instance.
-     *
-     * @param DateInterval $timeSpan Interval to be divided by.
-     * @return float $timeSpan Number that represents this instance divided by the value of $timeSpan.
-     */
-    public function divideTimeSpan(DateInterval $timeSpan): float {
-        $timeSpan = self::cast($timeSpan);
-
-        $days1 = $this->totalDays();
-        if($this->isNegative())
-            $days1 *= -1;
-
-        $days2 = $timeSpan->totalDays();
-        if($timeSpan->isNegative())
-            $days2 *= -1;
-
-        if($days2 === 0.0)
-            return 0.0;
-
-        return $days1 / $days2;
-    }
-
-    /**
-     * Returns the result of a division of this instance and the provided divisor.
-     *
-     * @param float $divisor Value to divide by.
-     * @return TimeSpan Instance that represents this instance divided by the value of $divisor.
-     */
-    public function divideFloat(float $divisor): TimeSpan {
-        $totalDays = $this->totalDays();
-        if($this->isNegative())
-            $totalDays *= -1;
-        $totalDays /= $divisor;
-        return self::fromDays($totalDays);
-    }
-
-    /**
-     * Returns a new TimeSpan whose alue is the result of a multiplication of this oinstance and the provided factor.
-     *
-     * @param float $factor Value to multiply with.
-     * @return TimeSpan Instance that represents this instance multiplied by the value of $factor.
-     */
-    public function multiply(float $factor): TimeSpan {
-        $totalDays = $this->totalDays();
-        if($this->isNegative())
-            $totalDays *= -1;
-        $totalDays *= $factor;
-        return self::fromDays($totalDays);
-    }
-
-    /**
-     * Return a new TimeSpan whose value is the negated value of this instance.
-     *
-     * @return TimeSpan Negated copy of this instance.
-     */
-    public function negate(): TimeSpan {
-        return self::create(
-            $this->getDays(),
-            $this->getHours(),
-            $this->getMinutes(),
-            $this->getSeconds(),
-            $this->getMicroseconds(),
-            !$this->isNegative()
-        );
-    }
-
-    public function compare(mixed $other): int {
-        if(!($other instanceof DateInterval))
-            return -1;
-        $other = self::cast($other);
-
-        $diff = $this->getDays() <=> $other->getDays();
-        if($diff) return $diff;
-
-        $diff = $this->getHours() <=> $other->getHours();
-        if($diff) return $diff;
-
-        $diff = $this->getMinutes() <=> $other->getMinutes();
-        if($diff) return $diff;
-
-        $diff = $this->getSeconds() <=> $other->getSeconds();
-        if($diff) return $diff;
-
-        $diff = $this->getMicroseconds() <=> $other->getMicroseconds();
-        if($diff) return $diff;
-
-        $diff = $this->isNegative() <=> $other->isNegative();
-        if($diff) return $diff;
-
-        return 0;
-    }
-
-    public function equals(mixed $other): bool {
-        if(!($other instanceof DateInterval))
-            return false;
-        $other = self::cast($other);
-        return $this->getDays() === $other->getDays()
-            && $this->getHours() === $other->getHours()
-            && $this->getMinutes() === $other->getMinutes()
-            && $this->getSeconds() === $other->getSeconds()
-            && $this->getMicroseconds() === $other->getMicroseconds()
-            && $this->isNegative() === $other->isNegative();
-    }
-
-    /**
-     * Returns the data which should be serialized as json.
-     *
-     * @see https://www.php.net/manual/en/jsonserializable.jsonserialize.php
-     * @return mixed Data to be passed to json_encode.
-     */
-    public function jsonSerialize(): mixed {
-        return (string)$this;
-    }
-
-    /**
-     * Creates a string representation of this object.
-     *
-     * @return string Representation of this object.
-     */
-    public function __toString(): string {
-        $string = $this->isNegative() ? '-' : '';
-        return sprintf(
-            '%sP%dY%dM%dDT%dH%dM%d.%dS',
-            $this->isNegative() ? '-' : '',
-            $this->y,
-            $this->m,
-            $this->d,
-            $this->getHours(),
-            $this->getMinutes(),
-            $this->getSeconds(),
-            $this->getMicroseconds()
-        );
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of days.
-     *
-     * @param float $days Number of days.
-     * @return TimeSpan Instance representing the provided number of days.
-     */
-    public static function fromDays(float $days): TimeSpan {
-        $abs = abs($days);
-        $round = (int)floor($abs);
-        $hours = ($abs - $round) * self::HOURS_IN_DAY;
-        $hoursRound = (int)floor($hours);
-        $minutes = ($hours - $hoursRound) * self::MINS_IN_HOUR;
-        $minsRound = (int)floor($minutes);
-        $seconds = ($minutes - $minsRound) * self::SECS_IN_MIN;
-        $secsRound = (int)floor($seconds);
-        $micros = (int)floor(($seconds - $secsRound) * self::MICROS_IN_SEC);
-        return self::create($round, $hoursRound, $minsRound, $secsRound, $micros, $days < 0);
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of hours.
-     *
-     * @param float $hours Number of hours.
-     * @return TimeSpan Instance representing the provided number of hours.
-     */
-    public static function fromHours(float $hours): TimeSpan {
-        $abs = abs($hours);
-        $round = (int)floor($abs);
-        $minutes = ($abs - $round) * self::MINS_IN_HOUR;
-        $minsRound = (int)floor($minutes);
-        $seconds = ($minutes - $minsRound) * self::SECS_IN_MIN;
-        $secsRound = (int)floor($seconds);
-        $micros = (int)floor(($seconds - $secsRound) * self::MICROS_IN_SEC);
-        return self::create(0, $round, $minsRound, $secsRound, $micros, $hours < 0);
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of minutes.
-     *
-     * @param float $minutes Number of minutes.
-     * @return TimeSpan Instance representing the provided number of minutes.
-     */
-    public static function fromMinutes(float $minutes): TimeSpan {
-        $abs = abs($minutes);
-        $round = (int)floor($abs);
-        $seconds = ($abs - $round) * self::SECS_IN_MIN;
-        $secsRound = (int)floor($seconds);
-        $micros = (int)floor(($seconds - $secsRound) * self::MICROS_IN_SEC);
-        return self::create(0, 0, $round, $secsRound, $micros, $minutes < 0);
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of seconds.
-     *
-     * @param float $seconds Number of seconds.
-     * @return TimeSpan Instance representing the provided number of seconds.
-     */
-    public static function fromSeconds(float $seconds): TimeSpan {
-        $abs = abs($seconds);
-        $round = (int)floor($abs);
-        $micros = (int)floor(($abs - $round) * self::MICROS_IN_SEC);
-        return self::create(0, 0, 0, $round, $micros, $seconds < 0);
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of milliseconds.
-     *
-     * @param float $millis Number of milliseconds.
-     * @return TimeSpan Instance representing the provided number of milliseconds.
-     */
-    public static function fromMilliseconds(float $millis): TimeSpan {
-        return self::fromMicroseconds($millis * 1000);
-    }
-
-    /**
-     * Creates a new TimeSpan instance that represents the specified number of microseconds.
-     *
-     * @param float $micros Number of microseconds.
-     * @return TimeSpan Instance representing the provided number of microseconds.
-     */
-    public static function fromMicroseconds(float $micros): TimeSpan {
-        return self::create(0, 0, 0, 0, (int)floor(abs($micros)), $micros < 0);
-    }
-
-    /**
-     * Creates a new TimeSpan using the given parameters.
-     *
-     * @param int $days Number of days.
-     * @param int $hours Number of hours.
-     * @param int $minutes Number of minutes.
-     * @param int $seconds Number of seconds.
-     * @param int $micros Number of microseconds.
-     * @param bool $negative true for a negative TimeSpan, false for positive.
-     * @return TimeSpan A new TimeSpan from the provided parameters.
-     */
-    public static function create(int $days, int $hours, int $minutes, int $seconds, int $micros = 0, bool $negative = false): TimeSpan {
-        $ts = new TimeSpan;
-        $ts->realDays = $days = max(0, $days);
-        $ts->h = max(0, min(23, $hours));
-        $ts->i = max(0, min(59, $minutes));
-        $ts->s = max(0, min(59, $seconds));
-        $ts->f = $micros / self::MICROS_IN_SEC;
-        $ts->invert = $negative ? 1 : 0;
-
-        // this may still be stupid
-        if($days > 0) {
-            $days /= 365;
-            $ts->y = (int)$days;
-            $days -= $ts->y;
-            $days *= 12;
-            $ts->m = (int)$days;
-            $days -= $ts->m;
-            $days *= 31;
-            $ts->d = (int)$days;
-        }
-
-        return $ts;
-    }
-
-    /**
-     * Creates a TimeSpan from the relative parts of a string.
-     *
-     * Uses the same parser as strtotime and the DateTime constructor internally.
-     *
-     * @param string $dateTime A date with relative parts.
-     * @return TimeSpan A TimeSpan representing the given
-     */
-    public static function createFromDateString(string $dateTime): TimeSpan {
-        return self::cast(parent::createFromDateString($dateTime));
-    }
-
-    /**
-     * Makes sure a DateInterval inheriting object is a TimeSpan instance.
-     *
-     * @param DateInterval $dateInterval Input object.
-     * @return TimeSpan If the input was a TimeSpan, the same instance will be returned.
-     *                  If the input was something else, a new TimeSpan instance will be returned based on the input.
-     */
-    public static function cast(DateInterval $dateInterval): TimeSpan {
-        if($dateInterval instanceof TimeSpan)
-            return $dateInterval;
-
-        $timeSpan = new TimeSpan;
-        $timeSpan->y = $dateInterval->y;
-        $timeSpan->m = $dateInterval->m;
-        $timeSpan->d = $dateInterval->d;
-        $timeSpan->h = $dateInterval->h;
-        $timeSpan->i = $dateInterval->i;
-        $timeSpan->s = $dateInterval->s;
-        $timeSpan->f = $dateInterval->f;
-        $timeSpan->invert = $dateInterval->invert;
-        $timeSpan->realDays = $timeSpan->calculateRealDays();
-        return $timeSpan;
-    }
-}
diff --git a/src/TimeZoneInfo.php b/src/TimeZoneInfo.php
deleted file mode 100644
index 5467cf0..0000000
--- a/src/TimeZoneInfo.php
+++ /dev/null
@@ -1,213 +0,0 @@
-<?php
-// TimeZoneInfo.php
-// Created: 2021-06-12
-// Updated: 2022-02-27
-
-namespace Index;
-
-use DateTimeInterface;
-use DateTimeZone;
-use JsonSerializable;
-use RuntimeException;
-use Stringable;
-
-/**
- * Represents a time zone.
- */
-class TimeZoneInfo extends DateTimeZone implements JsonSerializable, Stringable, IComparable, IEquatable {
-    private array|null $location = null;
-
-    private static bool $constructed = false;
-    private static TimeZoneInfo $utc;
-
-    /**
-     * Constructs a new TimeZoneInfo object.
-     *
-     * @param string $timeZone Time zone identifier.,
-     * @return TimeZoneInfo New instance of TimeZoneInfo.
-     */
-    public function __construct(string $timeZone) {
-        parent::__construct($timeZone);
-    }
-
-    /**
-     * @internal
-     */
-    public static function construct(): void {
-        if(self::$constructed)
-            throw new RuntimeException('Static constructor was already called.');
-        self::$constructed = true;
-        self::$utc = new TimeZoneInfo('UTC');
-    }
-
-    /**
-     * Gets a TimeZoneInfo instance representing the UTC (+00:00) time zone.
-     *
-     * @return TimeZoneInfo Instance representing UTC.
-     */
-    public static function utc(): TimeZoneInfo {
-        return self::$utc;
-    }
-
-    /**
-     * Gets the current default time zone.
-     *
-     * Uses date_default_timezone_get internally.
-     *
-     * @return TimeZoneInfo Instance representing the default time zone.
-     */
-    public static function default(): TimeZoneInfo {
-        return new TimeZoneInfo(date_default_timezone_get());
-    }
-
-    /**
-     * Sets the current default time zone.
-     *
-     * Uses date_default_timezone_set internally.
-     *
-     * @param DateTimeZone|string $timeZone Desired default time zone.
-     * @throws RuntimeException If an invalid time zone was supplied.
-     */
-    public static function setDefault(DateTimeZone|string $timeZone): void {
-        if($timeZone instanceof DateTimeZone)
-            $timeZone = $timeZone->getName();
-
-        if(!date_default_timezone_set($timeZone))
-            throw new RuntimeException('Invalid default time zone specified.');
-    }
-
-    /**
-     * Gets location info for a time zone.
-     *
-     * It makes more sense to use getCountryCode, getLatitude, getLongitude and getComments, if you can.
-     *
-     * @return array Location information.
-     */
-    public function getLocation(): array {
-        if($this->location === null)
-            $this->location = parent::getLocation();
-        return $this->location;
-    }
-
-    /**
-     * Gets the country code of the country which this time zone falls in.
-     *
-     * @return string Country code for this time zone.
-     */
-    public function getCountryCode(): string {
-        return $this->getLocation()['country_code'];
-    }
-
-    /**
-     * Gets the latitude of this time zone.
-     *
-     * @return float Latitude of this time zone.
-     */
-    public function getLatitude(): float {
-        return $this->getLocation()['latitude'];
-    }
-
-    /**
-     * Gets the longitude of this time zone.
-     *
-     * @return float Longitude of this time zone.
-     */
-    public function getLongitude(): float {
-        return $this->getLocation()['longitude'];
-    }
-
-    /**
-     * Gets location comments for this time zone.
-     *
-     * @return string Location comments.
-     */
-    public function getComments(): string {
-        return $this->getLocation()['comments'];
-    }
-
-    /**
-     * Gets the offset of this timezone relative to a given date/time instance.
-     *
-     * @param DateTimeInterface|null $dateTime Date/time to use as a base, null for UTC Now.
-     * @return int Offset relative to given date/time.
-     */
-    public function getOffset(DateTimeInterface|null $dateTime = null): int {
-        return parent::getOffset($dateTime ?? new DateTime('now', self::$utc));
-    }
-
-    /**
-     * Creates a string representation of this object.
-     *
-     * @return string Representation of this object.
-     */
-    public function __toString(): string {
-        $offset = $this->getOffset();
-        return sprintf(
-            '(UTC%s%s) %s',
-            $offset < 0 ? '-' : '+',
-            date('H:i', abs($offset)),
-            $this->getName()
-        );
-    }
-
-    /**
-     * Returns the data which should be serialized as json.
-     *
-     * @see https://www.php.net/manual/en/jsonserializable.jsonserialize.php
-     * @return mixed Data to be passed to json_encode.
-     */
-    public function jsonSerialize(): mixed {
-        return $this->getName();
-    }
-
-    public function compare(mixed $other): int {
-        if(!($other instanceof DateTimeZone))
-            return -1;
-        $other = self::cast($other);
-
-        $diff = $this->getOffset() <=> $other->getOffset();
-        if($diff) return $diff;
-
-        return strcmp($this->getName(), $other->getName());
-    }
-
-    public function equals(mixed $other): bool {
-        if(!($other instanceof DateTimeZone))
-            return false;
-        return $this->getName() === $other->getName()
-            || $this->getOffset() === self::cast($other)->getOffset();
-    }
-
-    /**
-     * Gets a list of all time zones.
-     *
-     * @param bool $ordered true if the list should be ordered, false if not.
-     * @param int $timeZoneGroup ID of a group to filter the generated list.
-     * @param string|null $countryCode Country to filter the generated list by.
-     * @return array Array containing the time zones.
-     */
-    public static function all(bool $ordered = false, int $timeZoneGroup = DateTimeZone::ALL, string|null $countryCode = null): array {
-        $timeZones = self::listIdentifiers($timeZoneGroup, $countryCode === null ? null : $countryCode);
-        $timeZones = XArray::select($timeZones, fn($id) => new TimeZoneInfo($id));
-
-        if($ordered)
-            $timeZones = XArray::sort($timeZones, fn($a, $b) => $a->compare($b));
-
-        return $timeZones;
-    }
-
-    /**
-     * Makes sure a DateTimeZone inheriting object is a TimeZoneInfo instance.
-     *
-     * @param DateTimeZone $timeZone Input object.
-     * @return TimeZoneInfo If the input was a TimeZoneInfo, the same instance will be returned.
-     *                      If the input was something else, a new TimeZoneInfo instance will be returned based on the input.
-     */
-    public static function cast(DateTimeZone $timeZone): TimeZoneInfo {
-        if($timeZone instanceof TimeZoneInfo)
-            return $timeZone;
-        return new TimeZoneInfo($timeZone->getName());
-    }
-}
-
-TimeZoneInfo::construct();
diff --git a/src/XDateTime.php b/src/XDateTime.php
new file mode 100644
index 0000000..1e72794
--- /dev/null
+++ b/src/XDateTime.php
@@ -0,0 +1,103 @@
+<?php
+// XDateTime.php
+// Created: 2024-07-31
+// Updated: 2024-07-31
+
+namespace Index;
+
+use DateTimeImmutable;
+use DateTimeInterface;
+use DateTimeZone;
+
+final class XDateTime {
+    private const COMPARE_FORMAT = 'YmdHisu';
+
+    public static function now(): DateTimeInterface {
+        return new DateTimeImmutable('now');
+    }
+
+    private static function toCompareFormat(DateTimeInterface|string|int $dt): string {
+        if($dt instanceof DateTimeInterface)
+            return $dt->format(self::COMPARE_FORMAT);
+
+        if(is_string($dt))
+            $dt = strtotime($dt);
+
+        return gmdate(self::COMPARE_FORMAT, $dt);
+    }
+
+    public static function compare(
+        DateTimeInterface|string|int $dt1,
+        DateTimeInterface|string|int $dt2
+    ): int {
+        return strcmp(
+            self::toCompareFormat($dt1),
+            self::toCompareFormat($dt2)
+        );
+    }
+
+    public static function compareTimeZone(
+        DateTimeZone|string $tz1,
+        DateTimeZone|string $tz2
+    ): int {
+        if(is_string($tz1))
+            $tz1 = new DateTimeZone($tz1);
+        if(is_string($tz2))
+            $tz2 = new DateTimeZone($tz2);
+
+        $now = self::now();
+        $diff = $tz1->getOffset($now) <=> $tz2->getOffset($now);
+        if($diff) return $diff;
+
+        return strcmp(
+            $tz1->getName(),
+            $tz2->getName()
+        );
+    }
+
+    public static function timeZoneListName(DateTimeZone $dtz): string {
+        $offset = $dtz->getOffset(self::now());
+        return sprintf(
+            '(UTC%s%s) %s',
+            $offset < 0 ? '-' : '+',
+            date('H:i', abs($offset)),
+            $dtz->getName()
+        );
+    }
+
+    public static function listTimeZones(bool $sort = false, int $group = DateTimeZone::ALL, string|null $countryCode = null): array {
+        $list = DateTimeZone::listIdentifiers($group, $countryCode);
+        $list = XArray::select($list, fn($id) => new DateTimeZone($id));
+
+        if($sort)
+            $list = XArray::sort($list, self::compareTimeZone(...));
+
+        return $list;
+    }
+
+    public static function format(DateTimeInterface|string|int|null $dt, string $format): string {
+        if($dt === null) {
+            $dt = time();
+        } else {
+            if($dt instanceof DateTimeInterface)
+                return $dt->format($format);
+
+            if(is_string($dt))
+                $dt = strtotime($dt);
+        }
+
+        return gmdate($format, $dt);
+    }
+
+    public static function toISO8601String(DateTimeInterface|string|int|null $dt): string {
+        return self::format($dt, DateTimeInterface::ATOM);
+    }
+
+    public static function toCookieString(DateTimeInterface|string|int|null $dt): string {
+        return self::format($dt, DateTimeInterface::COOKIE);
+    }
+
+    public static function toRFC822String(DateTimeInterface|string|int|null $dt): string {
+        return self::format($dt, DateTimeInterface::RFC822);
+    }
+}
diff --git a/tests/DateTimeTest.php b/tests/DateTimeTest.php
deleted file mode 100644
index a2a6549..0000000
--- a/tests/DateTimeTest.php
+++ /dev/null
@@ -1,386 +0,0 @@
-<?php
-// DateTimeTest.php
-// Created: 2021-06-14
-// Updated: 2024-07-31
-
-declare(strict_types=1);
-
-use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Attributes\CoversClass;
-use Index\DateTime;
-use Index\TimeSpan;
-use Index\TimeZoneInfo;
-
-#[CoversClass(DateTime::class)]
-#[CoversClass(TimeSpan::class)]
-#[CoversClass(TimeZoneInfo::class)]
-final class DateTimeTest extends TestCase {
-    public function testAttributes(): void {
-        $index = new DateTime('2021-06-14T21:07:14.359324 CEST');
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-        $this->assertEquals($index->getDayOfWeek(), DateTime::MONDAY);
-        $this->assertEquals($index->getDayOfYear(), 165);
-        $this->assertEquals($index->getWeek(), 24);
-        $this->assertTrue($index->isDaylightSavingTime());
-        $this->assertFalse($index->isLeapYear());
-        $this->assertFalse($index->isUTC());
-
-        $indexDate = $index->getDate();
-        $this->assertEquals($indexDate->getYear(), 2021);
-        $this->assertEquals($indexDate->getMonth(), 6);
-        $this->assertEquals($indexDate->getDay(), 14);
-        $this->assertEquals($indexDate->getHour(), 0);
-        $this->assertEquals($indexDate->getMinute(), 0);
-        $this->assertEquals($indexDate->getSecond(), 0);
-        $this->assertEquals($indexDate->getMillisecond(), 0);
-        $this->assertEquals($indexDate->getMicrosecond(), 0);
-        $this->assertEquals($indexDate->getDayOfWeek(), DateTime::MONDAY);
-        $this->assertEquals($indexDate->getDayOfYear(), 165);
-        $this->assertEquals($indexDate->getWeek(), 24);
-
-        $indexTime = $index->getTimeOfDay();
-        $this->assertEquals($indexTime->getHours(), 21);
-        $this->assertEquals($indexTime->getMinutes(), 7);
-        $this->assertEquals($indexTime->getSeconds(), 14);
-        $this->assertEquals($indexTime->getMilliseconds(), 359);
-        $this->assertEquals($indexTime->getMicroseconds(), 359324);
-    }
-
-    public function testTimeZone(): void {
-        $index1 = DateTime::utcNow();
-        $index2 = DateTime::now(new TimeZoneInfo('Australia/Melbourne'));
-        $this->assertEquals($index1->getUnixTimeSeconds(), $index2->getUnixTimeSeconds());
-    }
-
-    public function testSetters(): void {
-        $index = new DateTime('2021-06-14T21:07:14.359324 CEST');
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-
-        $index = $index->setDate(2005, 3, 9);
-        $this->assertEquals($index->getYear(), 2005);
-        $this->assertEquals($index->getMonth(), 3);
-        $this->assertEquals($index->getDay(), 9);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-
-        $index = $index->setISODate(2011, 20, 5);
-        $this->assertEquals($index->getYear(), 2011);
-        $this->assertEquals($index->getMonth(), 5);
-        $this->assertEquals($index->getDay(), 20);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-
-        $index = $index->setTime(10, 46, 50, 987654);
-        $this->assertEquals($index->getYear(), 2011);
-        $this->assertEquals($index->getMonth(), 5);
-        $this->assertEquals($index->getDay(), 20);
-        $this->assertEquals($index->getHour(), 10);
-        $this->assertEquals($index->getMinute(), 46);
-        $this->assertEquals($index->getSecond(), 50);
-        $this->assertEquals($index->getMillisecond(), 987);
-        $this->assertEquals($index->getMicrosecond(), 987654);
-
-        $index = $index->setTimestamp(1623702634);
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 22);
-        $this->assertEquals($index->getMinute(), 30);
-        $this->assertEquals($index->getSecond(), 34);
-        $this->assertEquals($index->getMillisecond(), 0);
-        $this->assertEquals($index->getMicrosecond(), 0);
-        $this->assertFalse($index->isUTC());
-    }
-
-    public function testUnixTimestamp(): void {
-        $index = DateTime::fromUnixTimeSeconds(1623696039);
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 18);
-        $this->assertEquals($index->getMinute(), 40);
-        $this->assertEquals($index->getSecond(), 39);
-        $this->assertEquals($index->getMillisecond(), 0);
-        $this->assertEquals($index->getMicrosecond(), 0);
-        $this->assertEquals($index->getUnixTimeSeconds(), 1623696039);
-        $this->assertEquals($index->getUnixTimeMilliseconds(), 1623696039000);
-        $this->assertTrue($index->isUTC());
-
-        $index = DateTime::fromUnixTimeMilliseconds(1623696422656);
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 18);
-        $this->assertEquals($index->getMinute(), 47);
-        $this->assertEquals($index->getSecond(), 2);
-        $this->assertEquals($index->getMillisecond(), 656);
-        $this->assertEquals($index->getMicrosecond(), 656000);
-        $this->assertEquals($index->getUnixTimeSeconds(), 1623696422);
-        $this->assertEquals($index->getUnixTimeMilliseconds(), 1623696422656);
-        $this->assertTrue($index->isUTC());
-    }
-
-    // verify the results of this at some point
-    public function testAdding(): void {
-        $index = new DateTime('2021-06-14T21:07:14.359324Z');
-
-        // Confirm initial state
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-
-        // Add
-        $index = $index->add(TimeSpan::create(1, 0, 10, 0));
-        $this->assertEquals($index->getDay(), 15);
-        $this->assertEquals($index->getMinute(), 17);
-
-        // Add years
-        $index = $index->addYears(1);
-        $this->assertEquals($index->getYear(), 2022);
-        $this->assertEquals($index->getMonth(), 6);
-        $index  = $index->addYears(1.5);
-        $this->assertEquals($index->getYear(), 2023);
-        $this->assertEquals($index->getMonth(), 12);
-
-        // Add months
-        $index = $index->addMonths(1);
-        $this->assertEquals($index->getMonth(), 12);
-        $this->assertEquals($index->getDay(), 16);
-        $index = $index->addMonths(1.5);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 15);
-
-        // Add days
-        $index = $index->addDays(1);
-        $this->assertEquals($index->getDay(), 16);
-        $this->assertEquals($index->getHour(), 21);
-        $index = $index->addDays(1.5);
-        $this->assertEquals($index->getDay(), 18);
-        $this->assertEquals($index->getHour(), 9);
-
-        // Add hours
-        $index = $index->addHours(1);
-        $this->assertEquals($index->getHour(), 10);
-        $this->assertEquals($index->getMinute(), 17);
-        $index = $index->addHours(1.5);
-        $this->assertEquals($index->getHour(), 11);
-        $this->assertEquals($index->getMinute(), 47);
-
-        // Add minutes
-        $index = $index->addMinutes(1);
-        $this->assertEquals($index->getMinute(), 48);
-        $this->assertEquals($index->getSecond(), 14);
-        $index = $index->addMinutes(1.5);
-        $this->assertEquals($index->getMinute(), 49);
-        $this->assertEquals($index->getSecond(), 44);
-
-        // Add seconds
-        $index = $index->addSeconds(1);
-        $this->assertEquals($index->getSecond(), 45);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-        $index = $index->addSeconds(1.5);
-        $this->assertEquals($index->getSecond(), 46);
-        $this->assertEquals($index->getMillisecond(), 859);
-        $this->assertEquals($index->getMicrosecond(), 859324);
-
-        // Add milliseconds
-        $index = $index->addMilliseconds(1);
-        $this->assertEquals($index->getMillisecond(), 860);
-        $this->assertEquals($index->getMicrosecond(), 860324);
-        $index = $index->addMilliseconds(1.5);
-        $this->assertEquals($index->getMillisecond(), 861);
-        $this->assertEquals($index->getMicrosecond(), 861824);
-
-        // Add microseconds
-        $index = $index->addMicroseconds(1);
-        $this->assertEquals($index->getMicrosecond(), 861825);
-        $index = $index->addMicroseconds(1.5);
-        $this->assertEquals($index->getMicrosecond(), 861826);
-    }
-
-    public function testSubtract(): void {
-        $index = new DateTime('2021-06-14T21:07:14.359324Z');
-
-        // Confirm initial state
-        $this->assertEquals($index->getYear(), 2021);
-        $this->assertEquals($index->getMonth(), 6);
-        $this->assertEquals($index->getDay(), 14);
-        $this->assertEquals($index->getHour(), 21);
-        $this->assertEquals($index->getMinute(), 7);
-        $this->assertEquals($index->getSecond(), 14);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-
-        // Subtract
-        $index = $index->subtract(TimeSpan::fromDays(400.12));
-        $this->assertEquals($index->getYear(), 2020);
-        $this->assertEquals($index->getMonth(), 5);
-        $this->assertEquals($index->getDay(), 10);
-        $this->assertEquals($index->getHour(), 18);
-        $this->assertEquals($index->getMinute(), 14);
-        $this->assertEquals($index->getSecond(), 26);
-        $this->assertEquals($index->getMillisecond(), 359);
-        $this->assertEquals($index->getMicrosecond(), 359324);
-    }
-
-    public function testDifference(): void {
-        $index1 = new DateTime('2021-06-14T21:07:14Z');
-        $index2 = DateTime::create(2013, 1, 27, 23, 14, 44, 0, new TimeZoneInfo('Europe/Amsterdam'));
-        $diff = $index1->difference($index2);
-
-        $this->assertEquals($diff->getDays(), 3061);
-        $this->assertEquals($diff->getHours(), 22);
-        $this->assertEquals($diff->getMinutes(), 52);
-        $this->assertEquals($diff->getSeconds(), 30);
-        $this->assertTrue($diff->isNegative());
-
-        $this->assertEquals($diff->totalDays(), 3061.953125);
-        $this->assertEquals($diff->totalHours(), 73486.875);
-        $this->assertEquals($diff->totalMinutes(), 4409212.5);
-        $this->assertEquals($diff->totalSeconds(), 264552750);
-        $this->assertEquals($diff->totalMilliseconds(), 264552750000);
-        $this->assertEquals($diff->totalMicroseconds(), 264552750000000);
-
-        $negated = $diff->negate();
-        $this->assertEquals($negated->getDays(), 3061);
-        $this->assertEquals($negated->getHours(), 22);
-        $this->assertEquals($negated->getMinutes(), 52);
-        $this->assertEquals($negated->getSeconds(), 30);
-        $this->assertFalse($negated->isNegative());
-    }
-
-    public function testModify(): void {
-        $index = new DateTime('2021-06-14T21:07:14Z');
-        $this->assertEquals($index->getMonth(), 6);
-
-        $index = $index->modify('+1 month');
-        $this->assertEquals($index->getMonth(), 7);
-    }
-
-    public function testCreate(): void {
-        $index = DateTime::create(2013, 1, 27, 23, 14, 44, 0, new TimeZoneInfo('Europe/Amsterdam'));
-        $this->assertEquals($index->getYear(), 2013);
-        $this->assertEquals($index->getMonth(), 1);
-        $this->assertEquals($index->getDay(), 27);
-        $this->assertEquals($index->getHour(), 23);
-        $this->assertEquals($index->getMinute(), 14);
-        $this->assertEquals($index->getSecond(), 44);
-
-        $index = $index->setTimezone(new TimeZoneInfo('UTC'));
-        $this->assertEquals($index->getHour(), 22);
-
-        $index = $index->setTimezone(new TimeZoneInfo('Asia/Tokyo'));
-        $this->assertEquals($index->getDay(), 28);
-        $this->assertEquals($index->getHour(), 7);
-
-        $index = $index->setTimezone(new TimeZoneInfo('America/New_York'));
-        $this->assertEquals($index->getDay(), 27);
-        $this->assertEquals($index->getHour(), 17);
-
-        $index = DateTime::createFromFormat('Y-m-d H:i:s', '2012-05-20 10:14:28');
-        $this->assertEquals($index->format('Y-m-d H:i:s'), '2012-05-20 10:14:28');
-
-        $this->assertFalse(DateTime::createFromFormat('Y-m-d H:i:s', 'mewow'));
-
-        $mutable = new \DateTime('2021-06-14T20:20:46Z');
-
-        $index = DateTime::createFromInterface($mutable);
-        $this->assertEquals($index->getUnixTimeMilliseconds(), (float)$mutable->format('Uv'));
-        $this->assertEquals($index->getTimezone()->getName(), '+00:00');
-
-        $index = DateTime::createFromMutable($mutable);
-        $this->assertEquals($index->getUnixTimeMilliseconds(), (float)$mutable->format('Uv'));
-    }
-
-    public function testToString(): void {
-        $dateTime = DateTime::create(2013, 1, 27, 23, 14, 44, 0, new TimeZoneInfo('Europe/Amsterdam'));
-        $this->assertEquals((string)$dateTime, '2013-01-27T23:14:44+01:00');
-        $this->assertEquals(json_encode($dateTime), '"2013-01-27T23:14:44+01:00"');
-        $this->assertEquals((string)$dateTime->toISO8601String(), '2013-01-27T23:14:44+01:00');
-        $this->assertEquals((string)$dateTime->toCookieString(), 'Sunday, 27-Jan-2013 23:14:44 CET');
-        $this->assertEquals((string)$dateTime->toRFC822String(), 'Sun, 27 Jan 13 23:14:44 +0100');
-
-        $dateTime = $dateTime->setTimezone(TimeZoneInfo::utc());
-        $this->assertEquals((string)$dateTime, '2013-01-27T22:14:44+00:00');
-        $this->assertEquals(json_encode($dateTime), '"2013-01-27T22:14:44+00:00"');
-        $this->assertEquals((string)$dateTime->toISO8601String(), '2013-01-27T22:14:44+00:00');
-        $this->assertEquals((string)$dateTime->toCookieString(), 'Sunday, 27-Jan-2013 22:14:44 UTC');
-        $this->assertEquals((string)$dateTime->toRFC822String(), 'Sun, 27 Jan 13 22:14:44 +0000');
-    }
-
-    public function testCompare(): void {
-        $index1 = new DateTime('2021-06-14T21:07:14Z');
-        $index2 = DateTime::create(2013, 1, 27, 23, 14, 44, 0, new TimeZoneInfo('Europe/Amsterdam'));
-
-        $this->assertGreaterThan(0, $index1->compare($index2));
-        $this->assertLessThan(0, $index2->compare($index1));
-        $this->assertEquals(0, $index1->compare($index1));
-    }
-
-    public function testEquals(): void {
-        $index1 = new DateTime('2021-06-14T21:07:14Z');
-        $index2 = DateTime::create(2013, 1, 27, 23, 14, 44, 0, new TimeZoneInfo('Europe/Amsterdam'));
-
-        $this->assertFalse($index1->equals($index2));
-        $this->assertFalse($index2->equals($index1));
-        $this->assertTrue($index1->equals($index1));
-    }
-
-    public function testCasting(): void {
-        $nativeDT = new \DateTime;
-        $this->assertInstanceOf(DateTime::class, $nativeDTCast = DateTime::cast($nativeDT));
-        $this->assertNotSame($nativeDT, $nativeDTCast);
-
-        $indexDT = new DateTime;
-        $this->assertInstanceOf(DateTime::class, $indexDTCast = DateTime::cast($indexDT));
-        $this->assertSame($indexDT, $indexDTCast);
-    }
-
-    public function testTimeZoneOrder(): void {
-        $all = TimeZoneInfo::all(true);
-        $lastOffset = null;
-        $lastString = null;
-
-        foreach($all as $timeZone) {
-            $offset = $timeZone->getOffset();
-            $string = $timeZone->getName();
-
-            if($lastOffset !== null) {
-                $diff = $lastOffset <=> $offset;
-                $this->assertLessThanOrEqual(0, $diff);
-
-                if($diff === 0)
-                    $this->assertLessThanOrEqual(0, $lastString <=> $string);
-            }
-
-            $lastOffset = $offset;
-            $lastString = $string;
-        }
-    }
-}
diff --git a/tests/XDateTimeTest.php b/tests/XDateTimeTest.php
new file mode 100644
index 0000000..66aef88
--- /dev/null
+++ b/tests/XDateTimeTest.php
@@ -0,0 +1,66 @@
+<?php
+// XDateTimeTest.php
+// Created: 2021-06-14
+// Updated: 2024-07-31
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+use Index\XDateTime;
+
+#[CoversClass(XDateTime::class)]
+final class XDateTimeTest extends TestCase {
+    public function testToString(): void {
+        $dateTime = new DateTime('2013-01-27T23:14:44', new DateTimeZone('Europe/Amsterdam'));
+        $this->assertEquals(XDateTime::toISO8601String($dateTime), '2013-01-27T23:14:44+01:00');
+        $this->assertEquals(XDateTime::toCookieString($dateTime), 'Sunday, 27-Jan-2013 23:14:44 CET');
+        $this->assertEquals(XDateTime::toRFC822String($dateTime), 'Sun, 27 Jan 13 23:14:44 +0100');
+
+        $dateTime = $dateTime->setTimezone(new DateTimeZone('UTC'));
+        $this->assertEquals(XDateTime::toISO8601String($dateTime), '2013-01-27T22:14:44+00:00');
+        $this->assertEquals(XDateTime::toCookieString($dateTime), 'Sunday, 27-Jan-2013 22:14:44 UTC');
+        $this->assertEquals(XDateTime::toRFC822String($dateTime), 'Sun, 27 Jan 13 22:14:44 +0000');
+
+        $this->assertEquals(XDateTime::toISO8601String(1359324884), '2013-01-27T22:14:44+00:00');
+        $this->assertEquals(XDateTime::toCookieString(1359324884), 'Sunday, 27-Jan-2013 22:14:44 GMT');
+        $this->assertEquals(XDateTime::toRFC822String(1359324884), 'Sun, 27 Jan 13 22:14:44 +0000');
+
+        $this->assertEquals(XDateTime::toISO8601String('January 27th 2013 22:14:44 UTC'), '2013-01-27T22:14:44+00:00');
+        $this->assertEquals(XDateTime::toCookieString('January 27th 2013 22:14:44 UTC'), 'Sunday, 27-Jan-2013 22:14:44 GMT');
+        $this->assertEquals(XDateTime::toRFC822String('January 27th 2013 22:14:44 UTC'), 'Sun, 27 Jan 13 22:14:44 +0000');
+    }
+
+    public function testCompare(): void {
+        $dt1 = '2021-06-14T21:07:14Z';
+        $dt2 = new DateTimeImmutable('2013-01-27T23:14:44', new DateTimeZone('Europe/Amsterdam'));
+
+        $this->assertGreaterThan(0, XDateTime::compare($dt1, $dt2));
+        $this->assertLessThan(0, XDateTime::compare($dt2, $dt1));
+        $this->assertEquals(0, XDateTime::compare($dt1, $dt1));
+        $this->assertEquals(0, XDateTime::compare($dt2, $dt2));
+    }
+
+    public function testTimeZoneOrder(): void {
+        $timeZones = XDateTime::listTimeZones(true);
+        $lastOffset = null;
+        $lastString = null;
+
+        $now = XDateTime::now();
+        foreach($timeZones as $timeZone) {
+            $offset = $timeZone->getOffset($now);
+            $string = $timeZone->getName();
+
+            if($lastOffset !== null) {
+                $diff = $lastOffset <=> $offset;
+                $this->assertLessThanOrEqual(0, $diff);
+
+                if($diff === 0)
+                    $this->assertLessThanOrEqual(0, $lastString <=> $string);
+            }
+
+            $lastOffset = $offset;
+            $lastString = $string;
+        }
+    }
+}
diff --git a/tools/update-headers.php b/tools/update-headers.php
index cb63a9b..cfceded 100644
--- a/tools/update-headers.php
+++ b/tools/update-headers.php
@@ -56,7 +56,7 @@ $files = array_merge($sources, $tests);
 
 $topDir = dirname(__DIR__) . DIRECTORY_SEPARATOR;
 
-$now = date('Y-m-d');
+$now = gmdate('Y-m-d');
 
 foreach($files as $file) {
     echo 'Scanning ' . str_replace($topDir, '', $file) . '...' . PHP_EOL;
diff --git a/tools/update-version.php b/tools/update-version.php
index 0a1acbc..ec5a913 100644
--- a/tools/update-version.php
+++ b/tools/update-version.php
@@ -3,7 +3,7 @@
 
 date_default_timezone_set('utc');
 
-$version = date('0.ym.jHi');
+$version = gmdate('0.ym.jHi');
 
 echo 'Updating VERSION file to ' . $version . PHP_EOL;