Date Calculator
Find days between dates or add/subtract time from any date
How the Date Calculator Works
The Days Between Dates tab counts the exact number of days, weeks, weekdays, and weekends between any two dates. It is useful for calculating deadlines, project timelines, or how long until a future event.
The Date Math tab lets you add or subtract days, weeks, months, or years from any starting date to find a resulting date. Useful for calculating expiration dates, 30/60/90-day deadlines, or planning ahead.
Worked example: from March 1 to March 15 is 14 days — not 15. The calculator counts the days you must advance to get from the start date to the end date, so the start date itself isn't counted as a full day. If you need an inclusive count (both endpoints counted, as in "a 15-day trial starting March 1"), add 1 to the result.
Common Deadline Calculations
Many legal, financial, and business deadlines are defined as a fixed number of days from a trigger date. Use the Date Math tab with the "Days" unit and today's date as the starting point to find these dates instantly:
| Deadline type | Typical length | Example use |
|---|---|---|
| Standard business deadline | 30 days | Net-30 invoice payment terms |
| Extended payment term | 60 days | Net-60 vendor contracts |
| Return / cancellation window | 90 days | Extended product return policies |
| Non-compete / notice period | 180 days | Employment agreement clauses |
| Pregnancy due date | 280 days (40 weeks) | Estimated from the first day of the last period |
| One year | 365 days (366 in a leap year) | Anniversary or contract renewal dates |
Frequently Asked Questions
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