Days Between Dates Calculator

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Count the days, weeks, months, years, business days and hours between two dates, or add and subtract days from a date.

Start Date

End Date

Include end date

Pick a start date and an end date.

About Days Between Dates Calculator

The OmniTools360 Days Between Dates Calculator counts the exact number of days between two dates, and also shows the gap in weeks and days, months and days, years, months and days, business days (Monday to Friday), and total hours. A second mode adds or subtracts days, weeks, months, or years from any date. It is free and runs in your browser.

How does the Days Between Dates Calculator work?

Each date is treated as a plain calendar day, so time zones and daylight saving changes cannot cause an off-by-one error. Total days are the difference between the two day numbers, plus one if you include the end date. Months and years are counted on the calendar, borrowing days from the previous month when needed. Business days count every Monday to Friday in the range.

Explanation

Total days = end date − start date (+1 if the end date is included). Weeks = floor(days / 7), remainder = days mod 7. Total hours = days × 24. Business days = number of Mondays to Fridays in the range; public holidays are not removed. When adding months, if the day does not exist in the target month, the last day of that month is used (31 January + 1 month = 28 or 29 February).

How to use the Days Between Dates Calculator

Select Days Between Dates, then choose a Start Date and an End Date.

Turn on Include end date if both the first and last day should be counted.

Read Total Days and the cards for weeks, months, years, business days, and hours.

To find a future or past date, select Add or Subtract, choose a Start Date, Operation, Amount, and Unit.

Click Copy to copy the result.

Days Between Dates Calculator examples

15 March 2026 to 4 July 2026 (end date not included)

111 days = 15 weeks and 6 days = 3 months and 19 days. Business days: 80. Total hours: 2,664.

1 January 2026 to 31 December 2026 with the end date included

365 days (52 weeks and 1 day), of which 261 are Monday to Friday business days.

17 October 2026 + 90 days

Friday, 15 January 2027.

Frequently Asked Questions about Days Between Dates Calculator

How do I calculate the number of days between two dates?

Subtract the start date from the end date. Enter both dates and the calculator gives the total instantly. For example, 15 March 2026 to 4 July 2026 is 111 days. If you need to count both the first and last day, such as for a hotel stay or leave request, turn on Include end date to add one day.

Should I include the end date?

It depends on what you are counting. Leave it off to measure elapsed time, such as days until a deadline or the length of a loan. Turn it on when both days count in full, such as a 1 to 5 June holiday, which is 5 days inclusive but only 4 days of elapsed time.

How are business days counted?

Business days are every Monday, Tuesday, Wednesday, Thursday, and Friday in the date range. Saturdays and Sundays are excluded and shown separately as weekend days. Public holidays differ by country and region, so they are not removed automatically. Subtract your local holidays from the result to get the exact number of working days.

How do I add days to a date?

Choose Add or Subtract, enter the Start Date, pick Add, type the number, and select Days, Weeks, Months, or Years. The resulting date and weekday appear immediately. For example, 17 October 2026 plus 90 days is Friday, 15 January 2027. Choose Subtract to count backwards from a date instead.

Does the calculator account for leap years?

Yes. The calculator uses the real calendar, so 29 February is counted in leap years such as 2028, and month lengths of 28, 29, 30, or 31 days are handled correctly. Dates are treated as whole local days, which avoids errors caused by daylight saving time changes. Nothing you enter leaves your browser.