Day of the Year Calculator

Day of the Year Calculator features

• 01

  Today's day number, instantly

  The current day of the year is shown as soon as the page loads, with the full date underneath and a copy button. No input, no clicking — the answer is the first thing on screen.

• 02

  Convert both directions

  Turn any calendar date into its day number, or enter a year and a day number to get the date back. Step forward and backward a day at a time to check the numbering around month ends and leap days.

• 03

  The context around the number

  Days remaining, year progress as a percentage, ISO week number, quarter, day of the quarter, and whether the year is a leap year — the details you usually need in the same breath as the day number.

Day of the Year Calculator FAQ

What day of the year is it today?

The number is displayed at the top of the page as soon as it loads, counted from 1 on January 1. The panel underneath shows how many days are left in the year and how far through the year you are as a percentage.

How many days are left in this year?

The days-remaining figure counts from tomorrow through to December 31, so on December 31 it reads zero. It automatically accounts for whether the current year has 365 or 366 days.

Is the day of the year the same as a Julian date?

In everyday industrial use, yes. Packaging codes, batch numbers and production schedules that say "Julian date" almost always mean the ordinal day of the year, 1 to 365 or 366, which is exactly what this tool gives you. Astronomers use a different Julian Day count that runs continuously from 4713 BC — that one is not what a date code on a product means.

How do I convert a date into its day number?

Pick the date in the date-to-day panel. The tool returns the day number, the weekday and the days remaining in that year. The arrows step one day at a time, which is a quick way to check how the numbering behaves across a month boundary.

How does a leap year change the day numbers?

In a leap year February 29 is day 60, and every date after it shifts up by one compared with a common year — March 1 is day 61 instead of 60, and December 31 is day 366. The calculator detects the leap year for whichever year you enter and adjusts automatically.