Millisecond clock a mock reads instead of Date.now().
Date.now()
const clock: MockClock = { now: () => 1_700_000_000_000 }; Copy
const clock: MockClock = { now: () => 1_700_000_000_000 };
Current wall time in milliseconds since the Unix epoch.
Millisecond clock a mock reads instead of
Date.now().Example