Values of the time_component_spec are
usually combined to specify times. The
io7m-jfprop uses
three values of type time_component_spec
to specify the times of day that mass synchronizations will be executed,
specifying the day, hour, and minute, respectively. As an example,
(any, divisible 2, exact 30)
specifies that a synchronization should run on all days, on even-numbered
hours, at 30 minutes past the hour.