The value of the object tTimeRangeActive indicates whether or not
the current time is in the time-range specification, and hence the
time-range can be considered as being 'active'.
A time-range is considered to be active each time the current date and
time maintained in this managed system
(TIMETRA-SYSTEM-MIB::stiDateAndTime) falls within one of the
range-entries defined for this time-range.