FAQ

  1. What clocks does this package provide?

    FastForward Clock provides two PSR-20 compliant implementations:

    • SystemClock : Returns the current system time (ideal for production)
    • FrozenClock : Returns a fixed time (ideal for testing)

  2. Which clock should I use in production?

    Use SystemClock or request Psr\Clock\ClockInterface from the container.

  3. Which interface should application services depend on?

    Prefer Psr\Clock\ClockInterface so the service contract remains portable across different clock implementations.

  4. How do I freeze time in tests?

    Use FrozenClock directly, or register it via an ArrayServiceProvider before ClockServiceProvider .

  5. Can I use this package without Fast Forward Container?

    Yes! Both SystemClock and FrozenClock are standalone classes that can be instantiated directly:

    $clock = new FastForward\Clock\FrozenClock('2026-04-07 10:00:00');

  6. Does this package require Fast Forward Container?

    No. The clocks work independently. The service provider is optional for container integration.

  7. How do I set a specific timezone?

    Pass a timezone string or DateTimeZone instance to the SystemClock constructor:

    $clock = new SystemClock('America/Sao_Paulo');

  8. Can I create my own clock implementation?

    Yes. Both clocks implement Psr\Clock\ClockInterface , so you can create any implementation that satisfies this interface.

  9. What's the difference between FrozenClock and MockClock?

    FrozenClock is a simple, standalone class that always returns the same time. It's perfect for most testing scenarios. If you need more advanced features like mocking sleep() calls, consider using Symfony's MockClock directly.

  10. Why use this package instead of creating my own clock?

    This package provides well-tested, PSR-20 compliant implementations that work seamlessly with Fast Forward Container and any PSR-11 compatible container. It also provides the service provider for easy integration.