Day Counter
Count the days between two dates, or add and subtract days from a date. The count handles month lengths and leap years and gives the same answer in every time zone. Along with the days you get weeks, calendar months and the number of weekdays.
How to use the Day Counter
- Choose Days Between Dates or Add or Subtract Days.
- For a count, pick the start and end dates. Tick Include the end date if both days should count, then press Count Days.
- To move a date, pick the start date, choose Add or Subtract, enter the number of days and press Calculate Date.
How the days are counted
Days = end date − start date · · · End date included: Days + 1 · · · Weeks = Days ÷ 7, the rest in days · · · Months = whole calendar months, the rest in days
The calculator subtracts calendar dates, not clock times, so a daylight saving change never adds or drops an hour that could round to a day. By default the start date counts and the end date does not, so Monday to Tuesday is 1 day. Ticking Include the end date adds 1. A whole month passes each time the day of the month of the start date comes around again. When a month is too short for that day, its last day stands in, so January 31 to February 28 is 1 month.
Worked example
From 2025-12-15 to 2026-05-26 is 162 days, which is 23 weeks and 1 day, or 5 months and 11 days. With the end date included it is 163 days. From 1900-01-01 to 2000-01-01 is 36,524 days, because 1900 was not a leap year and the century had 24 leap days.
Frequently asked questions
Does the day counter include the end date?
Only if you tick Include the end date. By default it counts the start date and leaves out the end date, which is the same as subtracting one date from the other. Monday to Tuesday is then 1 day. With the box ticked both dates count, and Monday to Tuesday is 2 days. The note under the result says which rule was used.
How are months counted?
By calendar month. A full month passes each time the day of the month of the start date comes around again, so January 15 to February 15 is 1 month however long January is. If a month has no such day, its last day counts instead. In 2026, January 31 to February 28 is 1 month, and January 31 to March 1 is 1 month and 1 day. In a leap year that month ends on February 29 instead.
Does it count business days?
It counts weekdays. The Weekdays row shows how many of the counted days fall on Monday to Friday and how many on a weekend. It does not know public holidays, so take those off yourself for a working-day count.
Do leap years and daylight saving time change the count?
Leap years do. February 29 counts in leap years such as 2024 and 2028. 1900 and 2100 are not leap years, and 2000 was. Daylight saving time does not, because the calculator works with whole dates and never looks at the clock.
What if the end date is before the start date?
The calculator counts forward from the earlier date and says so under the result. The number of days is the same either way round.