This sets the calendar date on which the timer's active window ends and it reverts to passive, with the description explicitly noting the timer simply won't be active at all if this stop date/time is already earlier than the current system date/time -- a real trap for an admin who leaves this at its 01/01/95 default while expecting the timer to run indefinitely. An admin configuring a long-running recurring schedule must deliberately set this to a date far enough in the future, since forgetting to update it from the vendor default effectively disables the entire timer from the moment it's configured. For example, an admin intending a timer to run for the next year must set this stop date to roughly a year out, not leave it at the 1995 placeholder, or the timer will never actually go active.