What day number is today?
Understand ordinal dates and find today's position in the year.
What an ordinal date means
The day of year is an integer from 1 through 365, or through 366 in a leap year. January 1 is day 1; December 31 is the final ordinal day.
How to calculate it
Add the days in every completed month to today's day of month. Date libraries are safer because they account for February automatically.
Where day numbers are used
Ordinal dates appear in manufacturing, logistics, astronomy and computer systems. They are compact, but should be paired with the year to avoid ambiguity.
Related year guides
- Leap years explained — Learn the Gregorian leap-year rule and why February sometimes has 29 days.
- How much of the year has passed? — Calculate the exact percentage of the current year that is complete.
- How to calculate year progress — A precise formula for calculating year progress in code or a spreadsheet.