Date Calculator
Count the days between two dates, or add or subtract years, months, weeks and days.
Two common jobs
Use the first tab to find out how long it is between two dates, in days, weeks and weekdays. Use the second to find the date that is a certain time before or after a start date.
Examples
From 1 January to 25 December 2026 is 358 days, or 11 months and 24 days. In the other tab, adding 1 month to 31 January 2026 gives 28 February, because February is shorter and the date moves to its last day.
Good to know
- Weekdays here mean Monday to Friday and do not remove public holidays.
- Choose “count the end date too” for inclusive counts, such as the nights and days of a trip.
- Dates are calendar dates, so time zones and daylight saving do not affect the result.
Frequently asked questions
How do I count business days?
The weekday figure counts Monday to Friday. Subtract any public holidays that fall on those days.
Why does adding a month sometimes change the day?
If the next month is shorter, the date moves to its last day, as with 31 January plus one month.
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