How it counts
day of year = date − January 1 + 1January 1 counts as day 1
- date
- the day you enter
- January 1
- day 1 of that year
- day of year
- the ordinal number, 1 to 365 or 366
Leap years have 366 days, so any date after February 29 sits one day higher than in a common year. Spreadsheets sometimes call this the ordinal or Julian day.
Frequently asked questions
What day of the year is it?
Leave the date on today; the day-of-year line shows the number, counting January 1 as day 1.
What day number is December 31?
Day 365 in a common year, or day 366 in a leap year.
How many days are left in the year?
The days-left line shows it, counting from your date to December 31.
Is this the same as the Julian day?
Spreadsheets often use "Julian day" for this ordinal number, though astronomers mean something different by the term.