Number of days between Dec 31, 9999 and Mar 25, 10001

Error: The date <big>Mar 25, 10001</big> could not be found.

Make sure you check for leap years. Try using one of the following formats for your entries:

      11/14/1932   (American format mm/dd/yyyy)

      1992-02-28   (MySQL and international format yyyy-mm-dd)

      November 27, 1984

      Jan 9, 1933

You can also enter words like:

      today

      yesterday

      1 year ago


Enter dates

Enter two dates below to find the number of days between them. For best results, avoid entering years before 1753. Examples include 1925-11-30 or Mar 4, 1939. You can also type words like today or yesterday, or use the American format, 10/13/2025.

Number of days between:
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Date calculator

This site provides an online date calculator to help you find the difference in the number of days between any two calendar days. Simply enter the start and end date to calculate the duration of any event. You can also use this tool to determine your age in days, or measure the amount of time until your baby's due date. The calculations use the Gregorian calendar, which was created in 1582 and later adopted in 1752 by Britain and the eastern part of what is now the United States. For best results, use dates after 1752 or verify any data if you are doing genealogy research. Historical calendars have many variations, including the ancient Roman calendar and the Julian calendar. Leap years are used to match the calendar year with the astronomical year. We are working on new pages for this site, so feel free to suggest any features you'd like to see!