Day of year calculator
The day of year counts from 1 January as day 1. In a common year 31 December is day 365; in a leap year it is 366. Anything after February shifts by one between the two.
How to find the day of the year
The ordinal date is what ISO 8601 calls this, written as 2026-235, and it turns up in aviation, manufacturing lot codes and older mainframe systems because it sorts and subtracts trivially. It is often loosely called a Julian date, which is a different thing; the true Julian Day Number counts days continuously from 4713 BC and is currently a seven-digit number, not one between 1 and 366.
Questions
Leave the date at today. The number and the days remaining are both shown.
It is an ordinal date, often called that loosely. A true Julian Day Number counts from 4713 BC and is seven digits.
Every date after February shifts by one, and the year has 366 days.
10 April in a common year, 9 April in a leap year.
Aviation, manufacturing lot codes, and older systems where dates need to sort and subtract easily.