By design, the Spotlight today alarm page keeps all old alarms.
If you would prefer that this was cleared, run the following sql query in the spotlight playback database to delete alarm history:
DELETE FROM [spotlight_playback_alarms] WHERE [pb_timestamp] < dateadd(day, -30, sysdatetime())
Note: The query above keeps alarms that are 30 days old.
We have a enhancement issued as SOSSE-1962 to redesign the alarm table to make deletion a much simpler task.
