Day of Year Calculator
Enter a date to see which numbered day of the year it is, and how many days remain.
Your calculation is performed in your browser.How it works
The calculator counts the exact number of calendar days from January 1 of your date's year up to and including your date, giving the day's position in the year.
Formula & methodology
The day of the year counts from January 1, which is day 1. The total length of the year is 366 in a leap year and 365 otherwise.
Day of year
Day of year = (Date − 1 January of that year) + 1Days remaining
Days remaining = Days in year − Day of yearYear elapsed
% of year elapsed = Day of year ÷ Days in year × 100What each term means
- Days in year
- 366 for a leap year, 365 for any other year.
Worked example
December 31 is day 365 of a common year, or day 366 in a leap year.
Common uses
- —Finding manufacturing or expiry date codes that use a day-of-year (Julian date) format.
- —Checking how far through the year a given date falls, and how many days remain.
- —Working with data formats or scheduling systems that reference day-of-year numbers.
Important notes
- —Leap years (366 days) are detected automatically, so the day count and days-remaining figure are always accurate for the specific year entered.