The number of seconds between two action invocations of
a periodic scheduler. Implementations must guarantee
that action invocations will not occur before at least
schedInterval seconds have passed.
The scheduler must ignore all periodic schedules that
have a schedInterval value of 0. A periodic schedule
with a scheduling interval of 0 seconds will therefore
never invoke an action.
Implementations may be forced to delay invocations in the
face of local constraints. A scheduled management function
should therefore not rely on the accuracy provided by the
scheduler implementation.
Note that implementations which maintain a list of pending
activations must re-calculate them when this object is
changed.