A 90-day window shows up constantly — a return policy, a probationary period, a visa’s permitted stay, or a contract notice period — and counting it out by hand on a calendar is easy to get wrong.
How it works
Adding 90 days (or any number you choose) to a start date, computed in UTC so daylight saving time never silently shifts the count by an hour into the wrong day.
What this does not include
This does not include business-day-only counting (skipping weekends and holidays) — this calculator counts every calendar day.
How to use this calculator
- Enter a start date. The number of days defaults to 90, but can be changed for any similar fixed-window question.
Frequently asked questions
Why 90 days specifically?
It’s a common legal and business standard — many return policies, probationary employment periods, and visa waiver programs are built around a 90-day window.
Does the day of the start date count as day 1?
No — this calculator adds a full 90 days to the start date, landing on the 91st day after (and including) the start date, consistent with how most “90 days from” deadlines are calculated.
Does this account for leap years?
Yes — the date arithmetic correctly passes through February 29 in a leap year without any adjustment needed.
