This request has shipped
The midnight alarm problem was better after the last update, but it still happens occasionally — usually after I have deleted several events at once. It feels like an old alarm is left behind somewhere and keeps ringing even though nothing in the app shows it.
Thank you for following up — and you were right about the cause. An alarm could be left registered on the device with no record of it inside the app, so cancelling never removed it. Version 1.7 enumerates every alarm registered on the device when cancelling, rather than only the ones the app remembers, so these leftovers are cleared as well. Sorry it took two attempts to fix.