Date Calculator
Count the days between dates, or add and subtract days, months, and years.
Enter the date as MM/DD/YYYY, for example 12/25/2026.
Date Calculator
The Date Calculator counts the days between two dates, or finds the date a set number of days, weeks, months, or years before or after another date. It accounts for leap years and the different lengths of months, and can skip weekends.
Days are counted as the difference between two dates, so November 1 to November 3 is 2 days.
How to use
- Choose Between dates or Add & subtract at the top.
- Type a date as eight digits (12252026) or pick it with the calendar button. Today sets that field to today.
- Read the result along with weeks, months, and weekdays.
Key terms
Two ways to count days
This calculator gives the difference between two dates. Counting both the start and end dates adds one more day. A hotel stay is counted as the difference, while an event that runs from one date to another often counts both ends, so Between dates shows both numbers.
| Example: Nov 1 to Nov 3 | Days |
|---|---|
| Difference | 2 days |
| Counting both ends | 3 days |
Adding weekdays
With Weekdays as the unit, counting starts the day after the start date and skips Saturdays and Sundays. The start date itself is not counted. Public holidays are not skipped, because they differ by country and year.
| Example: from Fri, Nov 6, 2026 | Result |
|---|---|
| +1 weekday | Mon, Nov 9, 2026 |
| +5 weekdays | Fri, Nov 13, 2026 |
Adding months
January 31 plus one month has no February 31, so the result is the last day of February (the 28th, or the 29th in a leap year). Adding one year to February 29 also gives February 28.
Leap years are not simply every four years
In the Gregorian calendar, a year divisible by 4 is a leap year, but a year divisible by 100 is not, unless it is also divisible by 400. That is why 2000 was a leap year and 2100 will not be.
Leap years in 400 years = 100 − 4 + 1 = 97
Why some dates are written 2026-12-25
The international standard ISO 8601 writes dates from the largest unit to the smallest, as YYYY-MM-DD. A date such as 01/05/22 can mean January 5 or May 1 depending on the country, so the standard sets one agreed order.
FAQ
Does the day count include the start date?
The result is the difference between the dates. The count that includes both the start and end dates is shown below it.
Are holidays left out of weekdays?
No. Only Saturdays and Sundays are left out, because public holidays differ by country and year.
Can I enter dates as DD/MM/YYYY?
The English page uses MM/DD/YYYY. You can also choose any date with the calendar button.
Are the dates I enter saved?
No. Dates are calculated in your browser and are never saved or sent to a server.