Self-explanatory.

This module may be used for time-sensitive FAQs (such as "When does registration
for this event begin?")  This question probably should not be displayed after
registration for the event is closed.

The ability to set an expiration date will reduce the amount of manual FAQ
management required by the admin.

Admins should be able to sort by expiration date (see expired, see expiring in
the next week, etc.)