Free Date Difference Calculator
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About the Date Difference Calculator
Calculate the number of days, weeks and months between two dates, or add and subtract days from a date — all in your browser with no upload.
How to use the Date Difference Calculator
- 1To measure a gap, pick a start date and an end date.
- 2See the difference in days, weeks and in years / months / days.
- 3Switch to the “add or subtract” tab to shift a date by a number of days.
- 4Everything is calculated in your browser — nothing is uploaded.
Frequently asked questions
Is this date calculator free?
Yes — completely free, with no sign-up and no watermark.
Is my data uploaded anywhere?
No. All date calculations run in your browser — nothing you enter is sent anywhere.
Does the day count include both the start and end date?
It counts the number of days between the two dates — so from the 1st to the 8th is 7 days. If you need to include both endpoints (for example counting event days), add one to the result.
Can I work out a date a certain number of days from now?
Yes — use the “add or subtract days” tab, enter a starting date and a number of days, and it shows you the resulting date. Use a negative number to go backwards in time.
Are leap years handled correctly?
Yes — the calculation uses the real calendar, so leap days are included in the day counts and in the years/months/days breakdown.