Web alarm clock for 9:52 p.m.
As you hand the church choir rehearsal over to another leader at 9:52 pm, an alarm can mark the moment for your final cue. Set it for 10:00 pm so the changeover does not interrupt a hymn halfway through or leave the next person guessing where to resume. The remaining minutes give you enough time to finish the current passage, mention any tricky entrance, and pass on the song sequence before the service.
During the choir handover, keep this alarm page open in the browser you used to set it and leave the phone or computer awake. If that browser is closed or the device falls asleep, the alarm may not sound, so the incoming leader could miss the agreed rehearsal stopping point. Check that the volume is audible above the singers, then place the screen where you can see the countdown without repeatedly pausing the group.
Voices, instruments, electric fans, and conversations near the church can still make the room lively late in the evening, though nearby traffic may ease as 10:00 pm approaches. Put the alarm close enough for the person taking charge to hear its first tone, but away from microphones or music stands where it could startle everyone. A brief vibration alongside the sound can provide a useful second signal amid the changing background noise.