A task time that represents the given duration amount of time.
A task time that represents the given amount of time in the given unit.
A task time that represents the given number of hours.
A task time that represents the given number of millis.
A task time that represents the given number of minutes.
A task time that represents the given number of seconds.
A task time that represents the given amount of ticks.
A task time that represents no time, for immediate execution.