SPUG: Looking for a schedule module for calendar/time-of-day checking

[James Moore]

I have to think someone's already written this, but so far I haven't found
it on CPAN.

I need a module that returns true if a given time fits into a schedule,
where a schedule could look something roughly like:

MoWeFr 10a-2p

or

29June 8a-5p

I don't care what the format of the schedule is; happy to use just about
anything that is vaguely legible to a human.

I need something that can do combinations of:

Day of the week
Time of day
Fixed dates
Xth Fooday of the month (3rd Fridays, first Mondays,.)

Anyone know of such a beast, or do I need to write it myself?

 - James