Day-of-Year Calculator

Find which numbered day of the year a date is, and how many days remain.

Worked example

December 31, 2028 is day 366 of that year, since 2028 is a leap year with 366 total days. In a non-leap year, December 31 is always day 365.

This is calendar arithmetic only; it does not reflect a fiscal or academic year, which often starts on a different date than January 1.

Does this account for leap years?: Yes, the total day count and every ordinal day after February 29 shift correctly in a leap year.