Date offset calculator
Add or subtract a whole number of calendar days from a YYYY-MM-DD date.
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How to use it
Select a start date and enter positive or negative days.
Good to know
Calculations use UTC calendar dates, avoiding daylight-saving time shifts.
Find a date before or after a known date
Choose a start date and enter a positive or negative day offset. Starting on 2026-01-01 and adding 30 returns 2026-01-31. Entering -7 moves a date back seven calendar days.
Use calendar dates, not elapsed local time
The calculation uses UTC calendar dates, so daylight-saving changes do not add or remove an hour from the result. It is suitable for plain date planning where the time of day is irrelevant.
It does not skip weekends or public holidays, and it does not create reminders or bookings. The resulting year must remain between 0000 and 9999.