How to Count the Days Between Two Dates

How do you count the days between two dates by hand?

Subtract the start day from the length of its month, add the length of each full month in between, then add the day number of the end date. This is the method to use with a calendar and no calculator.

Worked example: March 10 to June 25, 2026. March has 31 days, so 31 − 10 = 21 days remain. April and May are full months of 30 and 31 days. June contributes 25 days. The total is 107, the same figure the day counter returns.

Should you include the end date?

Exclude it when you want the time that passes between two dates, and include it when both the first and last day count as separate days. Excluding it is the default in our calculators, so a range from Monday to Tuesday is 1 day.

Think about what is being counted. A hotel stay from June 1 to June 5 is 4 nights, because you don't sleep there on the night of the 5th, so the end date stays out. A conference running June 1 through June 5 is 5 days, because people attend on all five, so the end date goes in. If a contract, notice period or application deadline depends on the count, read how that document defines it, since the wording decides which method applies.

Both the day counter and the date calculator have an "include end day" checkbox that adds 1 to the result.

How many days are in each month?

Seven months have 31 days, four have 30, and February has 28, or 29 in a leap year. The last column of the table gives a shortcut: the running total through the end of each month in a common year (one that isn't a leap year).

To use it, turn each date into its day of the year by adding the day number to the total for the previous month, then subtract. March 10 is 59 + 10 = 69, and June 25 is 151 + 25 = 176. The difference, 176 − 69, is 107. For dates after February in a leap year, add 1 to the running total. This works only within a single year.

How do leap years change the count?

A leap year adds 1 day to any range that crosses February 29. According to the US Naval Observatory, a Gregorian year divisible by 4 is a leap year, except that century years must also be divisible by 400. That made 2000 a leap year and means 1900 wasn't one and 2100 won't be. The next leap year after 2026 is 2028.

Ranges that don't reach February 29 are unaffected, even within a leap year. Our calculators apply the rule automatically, as the table shows.

How do you count business days?

Count the weekdays from Monday through Friday, then subtract any holidays that fall on those weekdays. Our two calculators stop at different points. The date calculator removes Saturdays and Sundays but not holidays. The day counter also removes US holidays and lists the ones it found.

The day counter starts with the 11 US federal holidays selected. You can turn each one off, add Black Friday, Christmas Eve or New Year's Eve, and type your own dates as month and day, such as 8/14. It doesn't know state, regional or other countries' holidays unless you enter them, and it doesn't know your employer's schedule.

Worked example: March 10 to June 25, 2026 has 107 days, of which 30 are weekend days and 77 are weekdays. Memorial Day and Juneteenth fall on weekdays in that range, which leaves 75 business days. As with the plain day count, the end date is left out unless you turn it on.

How do you count days in Excel or Google Sheets?

Subtract the earlier date from the later one: =B2-A2, with the start date in A2 and the end date in B2. Spreadsheets store dates as serial numbers, so plain subtraction gives the day count, with the end date excluded. Add 1 to include it. Format the result cell as a number if it displays as a date.

NETWORKDAYS needs care because it counts differently. Microsoft's own example returns 110 working days for October 1, 2012 to March 1, 2013, while the same range with the end date left out contains 109 weekdays. So NETWORKDAYS includes the end date when it falls on a weekday, which corresponds to turning on "include end day" in our calculators. For the March to June example, it should return 78 without a holiday list and 76 with the two holidays listed.

How do you count down to a date or add days to one?

For a countdown, enter today's date as the start and the event as the end. From November 4 to December 25, 2026 is 51 days, or 7 weeks and 2 days. To find a future date instead, use the add-or-subtract form on the date calculator: 90 days after November 4, 2026 is February 2, 2027.

When clock times matter too, use the time duration calculator, which has a form for the time between two dates. From March 10 at 8:00 AM to March 12 at 5:30 PM is 2 days, 9 hours and 30 minutes, or 57.5 hours. For shifts and payroll, see how to calculate hours worked. To turn a date range into an age in years, months and days, see how to calculate age.