Illustrative example. The dates and amounts below are provided for practice.
An event is scheduled for January 3, 2027 and the booking needs confirmation fourteen calendar days beforehand. A backward calculation can find the action date across the year boundary.
Choose Starting Date January 3, 2027, Custom Milestone, 14 days, and Before starting date. Target Date is December 20, 2026, Sunday.
Confirm the supplier's meaning
The interval from December 20 to January 3 is fourteen elapsed days. If a supplier says fourteen business days or excludes holidays, this result alone does not meet that rule. Check the supplier's definition and choose an earlier action date if necessary.
Inclusive numbering would call January 3 Day 15 when December 20 is Day 1. That does not reduce a stated fourteen-day lead time.
Store two linked intentions
Keep January 3 as the celebration and December 20 as a one-time preparation reminder. Put “Confirm booking” in the reminder title so the purpose is clear.
When the celebration moves, rerun the backward offset and edit the reminder. The tool does not automatically link the two saved dates or reschedule a task when its related event changes.