Day of Year
Find out what day of the year any date falls on — instantly, with a full-year calendar heatmap so you can see exactly where you are in the year.
What is an ordinal date?
The day of year — sometimes called the Julian day number in everyday use, or the ordinal date in ISO 8601 — is a compact way to identify a calendar day without specifying a month. Day 1 is always January 1; day 365 (or 366 in a leap year) is always December 31.
Ordinal dates appear in scheduling systems, agriculture, astronomy, and some database schemas where a plain integer is easier to work with than a full date string. They are also useful for quickly computing the number of days between two dates within the same year: subtract one day number from the other — or use Date Difference for dates spanning multiple years.
Frequently asked questions
What is the day of the year?
The day of year (also called the ordinal date) is a number from 1 to 365 — or 366 in a leap year — counting how many days have elapsed since January 1. January 1 is day 1; December 31 is day 365.
What day of the year is today?
The widget above calculates today's day number in real time from your device's clock. Nothing is sent to a server.
How many days are left in the year?
Days remaining equals the total days in the year (365 or 366 for a leap year) minus today's day number. Both values update whenever you change the date in the picker.
What is an ordinal date?
An ordinal date combines the year and the day-of-year number — for example 2026-173. It is defined in ISO 8601 and appears in scheduling systems, astronomy software, and some databases as a compact, unambiguous date representation.
How do I find the day number for a past or future date?
Use the date picker at the top of the widget. Select any date and the day number, days remaining, progress bar, and heatmap all update instantly.