All channels fire at this time when cards are due.

Fires while the course is open in a tab. No server needed.

Install the free ntfy app, subscribe to a private topic name, and enter that topic here. Scheduled pushes need the companion service; the test button works right now.

A morning email listing due cards and yesterday's recall rate. Wires to the scheduler worker's Resend sender in the build-out phase; the address is saved now.