This value represents the time between multiple test cycles.
This value is the length of time between the end of one test
cycle and the start of the next test cycle.
A new test cycle SHALL NOT begin while a current cycle is
running. Thus, this value SHOULD be greater than the result of
the number repetitions multiplied by the sum of the duration and
the frequency. If the value is less than the run time of a test
cycle, the overlapping test cycles are skipped.
For example, if there are two repetitions with a duration of 60
seconds and a frequency of 30 seconds, the test cycle runs for
180 seconds.
Notes: Maximum value is 90 days; a value of 86400 is one day.
A value of zero indicates this scheduled entry will not repeat
its test cycle.