I schedule reminder calls to myself before some important appointments. It keeps calling me until I receive the message which it reads me (I set the message when scheduling the reminder call) and I have to say "message received" which marks the notification as delivered. (I use Twilio to place the call.)

I find a phone call is more likely to get through to me than a reminder or alarm, which I can ignore or forget; an ordinary reminder is not as interactive.

Claude built it all and although there's a script for it, I just set the reminders in an interactive Claude code session in the directory. (Like I'll open a claude code session there and say "using the script in this directory, call me tomorrow at 7 a.m. with the message 'dr's appointment'."

It works well for me.