Choose what the endpoints mean
A date range needs a counting rule. From 1 June to 2 June, the default result is one day. This describes the distance from the first date to the next and is often useful for consecutive periods. If both 1 June and 2 June are days you want counted, include the end date to obtain two days.
For the same start and end date, the default result is zero. Including the end date makes it one. This difference is expected, not a rounding issue. Write down whether your result includes both endpoints when you share a booking period, a project window or an attendance count.
Count calendar days rather than estimate months
Calendar months have different lengths, so a day count is more precise than multiplying a number of months by 30. The calculator follows the entered calendar dates, including a valid 29 February in a leap year. It rejects an end date before the start date so a swapped range remains visible.
The total includes weekdays, weekends and holidays. It does not decide whether those dates are billable, working, school or leave days. For a work schedule that excludes selected weekdays and specific holidays, use the business days calculator with the applicable settings.
Separate dates from exact elapsed hours
This tool compares date labels, without a time of day or time zone. A calendar-day result should not be treated as proof of an exact number of real-world hours across a daylight-saving transition. If you have two clock times as well, use the time duration tool and read its wall-clock assumption.
Your browser may display dates in a familiar local order. Review the chosen month and day before calculating, especially when copying a numeric date from a document written for another region. Writing the month name in a shared report can help prevent ambiguity.
Worked example
Across a leap day
From 28 February 2028 to 1 March 2028 is 2 calendar days with the default end-exclusive rule. Counting both endpoints gives 3 calendar days: 28 February, 29 February and 1 March.
Common questions
Is the end date included?
The default excludes it. Select the include-end option when both the start and end dates should count.
Are weekends and public holidays included?
Yes. This is a calendar-day calculation. Use the business days calculator when you need selected dates excluded.
Why is the same date zero days?
There is no distance between identical dates. Select the inclusive option to count that date as one day.