NewSteppingClock creates a SteppingClock.

NewStoppedClock creates a StoppedClock.

NewSystemClock creates a system clock and returns it as a Clock.

SteppingClock is a Clock that returns a given series of time values, one at a time.

StoppedClock is a Clock that implements unchanging time.

SystemClock satisfies the Clock interface by supplying the system time.

Clock provides a clock service as an alternative to using the standard time package.