How to subtract time from a date
Find an earlier date by removing a duration from a known starting point.
What it means
Find an earlier date by removing a duration from a known starting point.
How to calculate or use it
Represent the starting point and duration consistently, then subtract using calendar-aware date functions.
Important details
State the time zone and distinguish elapsed hours from calendar days around daylight-saving changes.
Related before guides
- How to calculate hours before a time — Calculate the exact clock time a number of hours before another time.
- How to calculate weeks before a date — Move backward by complete seven-day periods.
- Before vs ago — Understand the difference between a relation to an event and a relation to now.