Keep the due time and plan an earlier prompt
Enter a due clock time and the number of minutes you need beforehand. This worksheet subtracts minutes on a plain 24-hour clock and shows the relative day. It sets no reminder, sends no notification and makes no timezone or daylight-saving calculation.
Use the two times differently
For the pickup example, the due time stays 17:00. The planning prompt is 15:30. A note can say: “Bring the collection slip and leave enough time to arrive by 17:00.” For a 00:20 deadline with 45 minutes of preparation, the prompt is 23:35 on the previous day. Choose the actual date in Reminders yourself.
If the interval crosses a clock change, a timezone change or a calendar deadline with special rules, determine the actual dates and times before creating the reminder. This worksheet cannot infer them.
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