Dart Duration in PHP - https://api.flutter.dev/flutter/dart-core/Duration-class.html

Duration.php

<?php

/**
 * Class Duration
 * Represents a time span with microsecond precision, similar to Dart's Duration class.
 */
class Duration
{
    /**
     * @var int Total duration in microseconds.
     */
    private int $microseconds;

    /**
     * Duration constructor.
     *
     * @param int $days
     * @param int $hours
     * @param int $minutes
     * @param int $seconds
     * @param int $milliseconds
     * @param int $microseconds
     */
    public function __construct(
        int $days = 0,
        int $hours = 0,
        int $minutes = 0,
        int $seconds = 0,
        int $milliseconds = 0,
        int $microseconds = 0
    ) {
        $this->microseconds =
            $days * 86_400_000_000 +
            $hours * 3_600_000_000 +
            $minutes * 60_000_000 +
            $seconds * 1_000_000 +
            $milliseconds * 1_000 +
            $microseconds;
    }

    /**
     * Create a Duration from a raw microsecond value.
     *
     * @param int $microseconds
     * @return Duration
     */
    public static function fromMicroseconds(int $microseconds): Duration
    {
        return new Duration(microseconds: $microseconds);
    }

    /**
     * @return int Duration in whole days.
     */
    public function inDays(): int
    {
      return intdiv($this->microseconds, 86_400_000_000);
    }

    /**
     * @return int Duration in whole hours.
     */
    public function inHours(): int
    {
      return intdiv($this->microseconds, 3_600_000_000);
    }

    /**
     * @return int Duration in whole minutes.
     */
    public function inMinutes(): int
    {
      return intdiv($this->microseconds, 60_000_000);
    }

    /**
     * @return int Duration in whole seconds.
     */
    public function inSeconds(): int
    {
      return intdiv($this->microseconds, 1_000_000);
    }

    /**
     * @return int Duration in whole milliseconds.
     */
    public function inMilliseconds(): int
    {
      return intdiv($this->microseconds, 1_000);
    }

    /**
     * @return int Duration in microseconds.
     */
    public function inMicroseconds(): int
    {
      return $this->microseconds;
    }

    /**
     * @return bool True if duration is negative.
     */
    public function isNegative(): bool
    {
      return $this->microseconds < 0;
    }

    /**
     * Get the absolute (positive) value of this Duration.
     *
     * @return Duration
     */
    public function abs(): Duration
    {
        return self::fromMicroseconds(abs($this->microseconds));
    }

    /**
     * Compare this duration to another.
     *
     * @param Duration $other
     * @return int Returns -1, 0, or 1
     */
    public function compareTo(Duration $other): int
    {
        return $this->microseconds <=> $other->microseconds;
    }

    /**
     * String representation of the duration.
     *
     * @return string
     */
    public function toString(): string
    {
        return (string) $this;
    }

    /**
     * Add another Duration to this one.
     *
     * @param Duration $other
     * @return Duration
     */
    public function add(Duration $other): Duration
    {
        return self::fromMicroseconds($this->microseconds + $other->microseconds);
    }

    /**
     * Subtract another Duration from this one.
     *
     * @param Duration $other
     * @return Duration
     */
    public function subtract(Duration $other): Duration
    {
        return self::fromMicroseconds($this->microseconds - $other->microseconds);
    }

    /**
     * Multiply this duration by a factor.
     *
     * @param int|float $factor
     * @return Duration
     */
    public function multiply(int|float $factor): Duration
    {
        return self::fromMicroseconds((int) round($this->microseconds * $factor));
    }

    /**
     * Integer divide this duration by a divisor.
     *
     * @param int $divisor
     * @return Duration
     * @throws \DivisionByZeroError
     */
    public function divide(int $divisor): Duration
    {
        if ($divisor === 0) {
            throw new \DivisionByZeroError("Cannot divide by zero.");
        }

        return self::fromMicroseconds(intdiv($this->microseconds, $divisor));
    }

    /**
     * Check equality with another Duration.
     *
     * @param Duration $other
     * @return bool
     */
    public function equals(Duration $other): bool
    {
        return $this->microseconds === $other->microseconds;
    }

    /**
     * Check if this duration is less than another.
     *
     * @param Duration $other
     * @return bool
     */
    public function lessThan(Duration $other): bool
    {
        return $this->microseconds < $other->microseconds;
    }

    /**
     * Check if this duration is less than or equal to another.
     *
     * @param Duration $other
     * @return bool
     */
    public function lessThanOrEqual(Duration $other): bool
    {
        return $this->microseconds <= $other->microseconds;
    }

    /**
     * Check if this duration is greater than another.
     *
     * @param Duration $other
     * @return bool
     */
    public function greaterThan(Duration $other): bool
    {
        return $this->microseconds > $other->microseconds;
    }

    /**
     * Check if this duration is greater than or equal to another.
     *
     * @param Duration $other
     * @return bool
     */
    public function greaterThanOrEqual(Duration $other): bool
    {
        return $this->microseconds >= $other->microseconds;
    }

    /**
     * Negate the duration (unary -).
     *
     * @return Duration
     */
    public function negate(): Duration
    {
        return self::fromMicroseconds(-$this->microseconds);
    }

    /**
     * Format the duration as HH:MM:SS.mmmuuu.
     *
     * @return string
     */
    public function __toString(): string
    {
        $micros = abs($this->microseconds);
        $sign = $this->microseconds < 0 ? '-' : '';

        $totalSeconds = intdiv($micros, 1_000_000);
        $microRemainder = $micros % 1_000_000;

        $hours = intdiv($totalSeconds, 3600);
        $minutes = intdiv($totalSeconds % 3600, 60);
        $seconds = $totalSeconds % 60;

        $milliseconds = intdiv($microRemainder, 1_000);
        $microseconds = $microRemainder % 1_000;

        return sprintf(
            "%s%02d:%02d:%02d.%03d%03d",
            $sign,
            $hours,
            $minutes,
            $seconds,
            $milliseconds,
            $microseconds
        );
    }
}