Calculate days between dates and identify the day of the week.
Calculator
Calendar Date Results
Date Difference Details
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Calendar day counter
Subtract the start date from the end date to count whole calendar-day boundaries. The result also identifies both weekdays and expresses the absolute span as complete weeks plus remaining days. The dates you enter are kept as calendar dates, without shifting them to your device's time zone.
signed day difference = end calendar date - start calendar date
complete weeks = round down(absolute days / 7); remaining days = remainder after complete weeks
Does the count include the end date?
The difference does not add an extra day for an inclusive count. January 1 to January 2, 2026 is 1 day: the endpoints are Thursday and Friday. The same start and end date gives 0 days. If your task counts both named dates, that two-date example contains 2 calendar dates; this tool still reports the difference of 1 day.
Leap days, weeks and reversed dates
February 28 to March 1, 2024 is 2 days because February 29 falls between them. The same endpoints in 2025 are 1 day apart. January 1 to January 10, 2026 is 9 days, or 1 complete week and 2 remaining days. Reversing those dates gives -9 days; the absolute span remains 1 week and 2 days, with the direction shown separately.
Calendar days are not stopwatch hours
The day count is independent of your device's time zone. A change of clocks for daylight saving does not add or remove a calendar date. This does not measure physical elapsed hours between time-zone-aware timestamps. It also does not divide by an average month length: a calendar month is not a fixed number of days.
Business days and deadline rules
Every calendar day counts, including weekends and holidays. There is no business-day calendar, holiday lookup, filing rule, payroll rule or automatic deadline adjustment. Use the rules governing your specific task instead of treating this general day difference as a deadline determination. Supported inputs are valid Gregorian calendar dates from year 0001 through 9999; the same calendar is applied to historical dates rather than reconstructing local calendar adoption.
Related date and duration tools
Use the age calculator for calendar years, months and days, or the time duration calculator when both endpoints also have clock times. Neither a plain day count nor a fixed-hour conversion determines holiday or legal deadline rules.