Days Between Dates Calculator
Pick two dates. You get the number of days between them, the same span in weeks and in calendar months, and the working days.
Updated
October 13, 2026 to December 25, 2026
73 days
How the days are counted
The calculator turns both dates into a day number and subtracts one from the other. That is the same as counting on a calendar from the day after the start date up to and including the end date.
days between = end date − start date
Weeks are that number divided by seven, with the remainder shown as extra days. The calendar breakdown moves forward from the start date in whole months first, then counts what is left.
Worked example
From October 12, 2026 to December 25, 2026:
- Rest of October: 31 − 12 = 19 days.
- All of November: 30 days.
- December up to the 25th: 25 days.
- 19 + 30 + 25 = 74 days, which is 10 weeks and 4 days.
- On the calendar: October 12 to December 12 is 2 months, and 13 more days reach December 25.
Days in each month
| Month | Days | Month | Days |
|---|---|---|---|
| January | 31 | July | 31 |
| February | 28, or 29 in a leap year | August | 31 |
| March | 31 | September | 30 |
| April | 30 | October | 31 |
| May | 31 | November | 30 |
| June | 30 | December | 31 |
A year is a leap year when it divides by 4, except century years, which must divide by 400: 2028 and 2000 are leap years, 2100 is not.
Frequently asked questions
Does the count include the start and end dates?
By default it counts the days from the start date to the end date, the way you would count nights: January 1 to January 2 is 1 day. Tick "Count the first day too" to include both dates, which is how a hotel counts days of a stay or a contract counts a notice period that starts today.
How are months and years counted?
As whole calendar months from the start date, with the leftover days after the last full month. March 15 to May 20 is 2 months and 5 days. Months have different lengths, so the same number of days can be a different number of months depending on where you start.
What counts as a working day?
Monday to Friday. Tick the holiday box to also leave out the eleven US federal holidays, on the day they are observed: the Friday before when a holiday falls on a Saturday, the Monday after when it falls on a Sunday.
Do leap years and daylight saving time affect the result?
Leap days are counted like any other day, so a span across February 29 is one day longer. Daylight saving time has no effect, because the calculator works on calendar dates, not on clock hours.
Sources
- 5 U.S.C. 6103: Holidays — the federal holidays and the weekend rule used for working days