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Date Calculator

Days between two dates, or a date plus or minus any amount of time.

Enter two valid dates.

How the counting works

Each date is turned into a plain count of days since 1 January 1970, the two counts are subtracted, and that's the answer. No months of "about 30 days", no rounding. The years-months-days breakdown steps forward whole months from the start date and counts the leftover days, the way you would on a paper calendar: 31 January to 1 March is 1 month and 1 day.

End date included or not? Counting from Monday to Friday gives 4 days by default: the number of midnights you cross. If you're counting days of an event where both the first and last day count (a festival, a course, a hospital stay for billing), include the end date.

Counting down to one date? The countdown keeps a live timer and saves your events.

Questions people ask

How do I count the days between two dates?
Enter a start and end date. By default the end date is not counted (1 to 2 January is 1 day), which is how most people and spreadsheets count. Tick "include end date" to count both, e.g. for a hotel stay counted in days rather than nights.
How are months added when the day doesn't exist?
Adding a month to 31 January gives the last day of February (28th, or 29th in a leap year). This end-of-month rule matches most spreadsheets and programming libraries.
How far back does it work?
Any date from 1 January of year 1 to 31 December 9999, in the proleptic Gregorian calendar.
Does it account for leap years and time zones?
Leap years, yes, exactly. Time zones and daylight-saving changes don't affect whole-day counts because the calculator works on calendar dates, not clock times.