Date Difference Calculator

Count the number of days between two dates, and see the difference in weeks, months and years, hours and minutes, with an option to include the end date.

How to use the date Difference Calculator

  1. Pick the start date.
  2. Pick the end date.
  3. Tick Include the end date (add 1 day) if you want that option; leave it clear otherwise.
  4. The result updates instantly as you type. There is no button to press.
  5. Use Copy result to copy the figures, or Copy link to share a link that reopens the date Difference Calculator with the same inputs.

How it works

How many days until a holiday, a wedding or a deadline? How long ago was a particular event? This calculator counts the calendar days between any two dates, accounting for months of different lengths and leap years, and also expresses the gap in weeks, in years, months and days, and in hours and minutes.

By default it counts the way most people and most software do: from the start date up to, but not including, the end date. So from Monday to the following Monday is 7 days. Tick Include the end date to count both ends, which is what you want when counting the days of an event, a trip or a hotel stay where the first and last days both count. That adds one day.

The calculation uses whole calendar days, so it isn't thrown off by daylight saving time changes, which make some days 23 or 25 hours long. The "approximate" month and year figures divide by the average length of a month (30.44 days) and year (365.2425 days) in the Gregorian calendar. For business deadlines that skip weekends and holidays, use the working days calculator instead.

Formula

days = (end date − start date) in whole calendar days (+1 if inclusive) weeks = ⌊days / 7⌋ remainder days mod 7 approximate months = days / 30.436875 approximate years = days / 365.2425

Example

From January 1, 2026 to March 1, 2026 is 31 days of January plus 28 of February: 59 days, or 8 weeks and 3 days, or exactly 2 months. In 2028, a leap year, the same dates are 60 days apart. Counting a festival from June 12 to June 15 inclusively gives 4 days.

Frequently asked questions

Does the count include the start and end dates?

It includes the start date but not the end date, so Monday to Tuesday is 1 day. Tick 'Include the end date' to count both, which adds one day.

Does it account for leap years?

Yes. It uses the real calendar, so February has 29 days in leap years such as 2028 and 2032.

Can I count backwards to a past date?

Yes. If the end date is earlier than the start date, the calculator swaps them and reports the difference.