Date Calculator
Count the days between two dates, or add and subtract days, weeks, months and years from a date.
How the date calculator counts days
The calculator subtracts the start date from the end date, the same way a calendar count works. From 1 January 2024 to 31 December 2024 gives 365 days, because the end date is not part of the count. Ticking "Include the end date" adds one day, so the same range gives 366 days. Hotel nights and loan periods usually leave out the end date, while event lengths and leave requests often count both the first and the last day.
Years, months and days
The breakdown counts whole calendar months first and then the remaining days. Months differ in length, so 31 January plus one month lands on the last day of February: 28 February in 2025 and 29 February in a leap year. The add and subtract mode follows the same rule, and adding one month to 31 March gives 30 April. Years and months are applied first, then weeks and days.
Business days
Business days run from Monday to Friday. The count leaves out Saturdays and Sundays but keeps public holidays, because holidays differ by country and region. Subtract any holidays in the range by hand for an exact working-day figure. When adding business days, a weekend start date counts from the next weekday, so Saturday plus one business day gives Monday.
Leap years and daylight saving time
A leap year has 366 days. Years divisible by 4 are leap years, except century years, which also need to be divisible by 400. The year 2000 was a leap year and 1900 was not. The calculator works with whole calendar dates rather than clock times, so a daylight saving change inside the range never adds or removes a day. Hours, minutes and seconds assume 24-hour days.
Sharing a calculation
The "Copy share link" button creates a URL holding the current inputs, for example minitool.app/date-calculator/?start=2026-01-01&end=2026-12-25. Opening the link fills in the same calculation. The browser also keeps the last inputs for the next visit, and nothing leaves the device.