Day of Year Calculator
Free online day of year calculator. Find the day number for any date, days remaining in the year, and leap year status instantly.
About This Free Online Day of Year Calculator
Our free day-of-year calculator tells you which numbered day of the year any date falls on, so January 1 is day 1 and December 31 is day 365, or 366 in a leap year. Pick a date and the tool returns its day number instantly, and it can also tell you how many days remain in the year. This ordinal day number, sometimes called the Julian day of the year, is used in scheduling, scientific and agricultural records, programming, and data analysis. It correctly accounts for leap years so your result is always accurate. Working this out by hand means counting through every month, which is slow and error-prone. The calculator runs entirely in your browser with instant results, so there is no signup, and nothing you enter is sent to a server.
Features of Our Day of Year Calculator
- Day number (1-365/366) for any date
- Days remaining in the current year
- Leap year detection
- Week number and day name display
- Real-time update as you change date
- 100% free and private
How to Use the Day of Year Calculator
The Day of Year Calculator works right in your browser — no signup, no installation. Follow these steps:
- Select a date using the date picker or click Today.
- View the day number, week number, and day name.
- Check days remaining in the year.
- Copy the result formatted as text.
Frequently Asked Questions About Day of Year Calculator
What is the day of year?
The day of year (also called ordinal date or Julian date) is a number from 1 to 365 (or 366 in leap years) representing the sequential day count within a calendar year. January 1 is day 1, February 1 is day 32, and so on.
What is a leap year?
A leap year has 366 days instead of 365, with an extra day on February 29. Leap years occur every 4 years, except for century years not divisible by 400 (e.g., 1900 was not a leap year, but 2000 was).
How many days are in each month?
January 31, February 28/29, March 31, April 30, May 31, June 30, July 31, August 31, September 30, October 31, November 30, December 31.
Why Choose the Day of Year Calculator?
The Day of Year Calculator gives you exact dates and durations without manual counting. It calculates instantly in your browser, accounts for the cases people actually need, and keeps whatever you enter on your own device.