Days Between Dates

How the count works

The calculator returns the number of days between the start date and the end date, using the real calendar — month lengths and leap years are handled automatically. The count is exclusive of the start date: from Monday to the following Monday is 7 days.

Worked examples

• From 1 January to 25 December 2026: 358 days.
• From 13 October 2026 to 14 July 2027: 274 days, about 39 weeks.
• From 1 January 2024 to 31 December 2024: 365 days, because 2024 was a leap year with 29 February.

Inclusive or exclusive?

It depends on what you are counting:

• Duration (age of a project, time until an event): use the result as shown.
• Number of days covered (a hotel booking from the 3rd to the 7th inclusive, days of leave, a festival): add 1 if both the first and last day count. A rental from 3 to 7 August covers 5 days but 4 nights.

Converting the result

• Weeks: divide by 7 (274 days = 39 weeks and 1 day).
• Months: divide by about 30.44, the average month length — months vary from 28 to 31 days, so exact month counts depend on the dates.
• Years: divide by 365.25 to account for leap years.

Leap years

A year is a leap year if it is divisible by 4, except century years, which must be divisible by 400. So 2000 was a leap year but 1900 was not. The next leap years are 2028, 2032 and 2036.

Good to know

• The order of the dates doesn't matter: the result is always positive.
• The calculator counts calendar days. Working days exclude weekends and public holidays, which vary by country and region.
• Legal and contractual deadlines often have their own counting rules (for example, a period ending on a Sunday may be extended to the next working day) — check the applicable rules.

Formulas and content last reviewed: October 2026 · About