The day of the year is a date's ordinal position within its year — January 1 is day 1, and December 31 is day 365 in a common year or day 366 in a leap year. This calculator returns the day number, the days remaining, the weekday, and the percent of the year elapsed for any date you enter.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: Gregorian calendar, recomputed in code.
How it's counted
Because February has 29 days in a leap year, the same calendar date can have a different day number depending on the year. From March onward, every date in a leap year sits one day later than in a common year. The total days in the year — 365 or 366 — sets the maximum, and the days remaining is simply that total minus the day number.
Worked examples
July 4, 2024 (leap year):
March 1 — leap vs common:
December 31:
So on July 4, 2024, 180 days remain in the year and roughly 50.8% has elapsed. The weekday for that date is Thursday — the calculator reports all of these at once.
Frequently Asked Questions
The ordinal position of a date in its year. Jan 1 = day 1; Dec 31 = day 365 or 366. Mar 1, 2024 = day 61.
Add the lengths of all earlier months, then add the day. Jul 4 leap year: 182 + 4 = 186.
365 common, 366 leap. Day 366 appears only in leap years (÷4, century years ÷400).
No. Astronomical Julian Day counts from 4713 BC. Day of year (1–366) is within one year.
Total days minus the day number. Day 186 of 366 → 180 remaining.