Day of the Year Calculator

Find the date for a day number

Enter a year and a day number from 1 to 365 (366 in a leap year) and the calculator gives the calendar date and weekday. Today is Monday, October 5, 2026, which is day 278 of 2026. Also in 2026: day 100 of 2026 is Friday, April 10, 2026, day 200 of 2026 is Sunday, July 19, 2026, day 300 of 2026 is Tuesday, October 27, 2026.

Ordinal dates

A day-of-year number is also called an ordinal date. It is used in logistics, aviation, manufacturing lot codes, satellite data and food packaging, and the ISO 8601 format writes it as YYYY-DDD. In a leap year every date after February 28 has a day number one higher than in a common year.

How to check by hand

January has 31 days, so February 1 is day 32. In a common year March 1 is day 60, April 1 is day 91, May 1 is day 121, June 1 is day 152, July 1 is day 182, August 1 is day 213, September 1 is day 244, October 1 is day 274, November 1 is day 305 and December 1 is day 335. Add 1 to each of them from March in a leap year.

Frequently asked questions

What is today's day number?

Day 278 of 2026.

What date is day 100?

Friday, April 10, 2026 in 2026.

What date is day 200?

Sunday, July 19, 2026 in 2026.

What date is day 365?

December 31 in 2026.

What is day 366?

December 31, in leap years only.

What day number is March 1?

60 in a common year and 61 in a leap year.

Is 2026 a leap year?

No.

What is an ordinal date?

A date written as the year and the day number.

Day numbers 1 to 92 of 2026

Day numbers 93 to 184 of 2026

Day numbers 185 to 276 of 2026

Day numbers 277 to 365 of 2026

Day numbers 1 to 92 of 2027

Day numbers 93 to 184 of 2027

Day numbers 185 to 276 of 2027

Day numbers 277 to 365 of 2027