Getting Services

This section explains how to retrieve clock services in your application.

Direct instantiation

You can use clock classes directly without any container:

Class	Description
`FastForward\Clock\SystemClock`	Returns current system time with optional timezone
`FastForward\Clock\FrozenClock`	Returns fixed time for deterministic testing
`Psr\Clock\ClockInterface`	Interface implemented by both clock classes

Example with SystemClock:

<?php

declare(strict_types=1);

use FastForward\Clock\SystemClock;

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

echo $clock->now()->format(DATE_ATOM) . PHP_EOL;

Example with FrozenClock:

<?php

declare(strict_types=1);

use FastForward\Clock\FrozenClock;

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

echo $clock->now()->format(DATE_ATOM) . PHP_EOL;

Via Fast Forward Container

ClockServiceProvider exposes the following service identifiers:

Service ID	Resolved instance
`FastForward\Clock\SystemClock`	A system clock created by the provider
`Psr\Clock\ClockInterface`	Alias to the registered `SystemClock` instance
`FastForward\Clock\FrozenClock`	A frozen clock factory (not pre-instantiated)

You can retrieve any of them from the container:

<?php

declare(strict_types=1);

use FastForward\Clock\ServiceProvider\ClockServiceProvider;
use Psr\Clock\ClockInterface;
use FastForward\Clock\SystemClock;
use FastForward\Clock\FrozenClock;
use function FastForward\Container\container;

$container = container(new ClockServiceProvider());

$systemClock = $container->get(SystemClock::class);
$psrClock = $container->get(ClockInterface::class);
$frozenClock = $container->get(FrozenClock::class);

assert($systemClock === $psrClock);

Prefer Psr\Clock\ClockInterface in application services for maximum portability. Use specific implementations when you need particular features like timezone control or time freezing.