This setup uses an iPhone Shortcut to open Daybook and save a flag, then add a discreet reminder 20 minutes later. For reliable saving, open it using normal Safari browsing (not Private).

1. In Shortcuts, tap + and name it “Flag moment”.
2. Add a URL action and paste the flag link below. Then add Open URLs immediately after it.
3. Add Current Date, followed by Adjust Date (+20 minutes).
4. Add Add New Reminder, title it “Review time card”, and set its alert date to the adjusted date. If necessary expand its options to set the alert.
5. Run it once while Safari is in normal browsing mode; check that Daybook shows a new flag and Reminders has a scheduled alert. Only after testing add the shortcut as a Control Center control.

This version briefly opens Daybook to record the flag. If Safari opens it in a different browsing profile, the flag may not appear alongside your entries. Always confirm after testing. No reminder is scheduled by Daybook itself.

Quickest option with no setup: say "Hey Siri, remind me in 20 minutes to review my time card."

The neutral title is visible on your lock screen; the actual flagged moments are only shown in Daybook. Don't include personal details in the reminder title. iOS menu names may differ.

To truly flag a moment with one Control Center tap, we would need to install Daybook as a hosted app or build an iPhone Shortcut that writes to a shared file; this offline HTML version does not do that yet.