One of the choices from the drop-down list of frequencies is the use of "ad hoc."

An ad hoc alert can be created with a "first release" date and an "expiration date."

At expiration, a second email message is released informing the staff that the compliance-alert described is no longer in effect.

Example: Authorized Iranian humanitarian relief and reconstruction donations that had a 90-day window as a result of an earthquake in December 2003.