Change when clients get reminded

Open Menu, then SETTINGS, then Notifications, and find "Remind clients this far ahead".

The options are 2 hours, 1 day, 2 days, 3 days, and 1 week.

Match it to how far ahead people book you. A week is useful when clients book months out and need warning to arrange their day. Two hours suits walk-in-ish businesses where the reminder is really just a nudge on the day.