Day of the year
Day of the year is the count from 1 January. 1 January is day 1. 31 December is day 365, or 366 in a leap year under the Gregorian rule. Days left are the whole days after the chosen date through 31 December. This page does not replace the week-number tool.
What day of the year is this date
ISO week numbers live on the week number tool.
Day of the year FAQ
Is 1 January day 1?
Yes. 31 December is day 365, or 366 in a leap year. Days left are the whole days after the chosen date through 31 December.
How is a leap year decided?
The Gregorian rule: divisible by 4, except centuries that are not divisible by 400. Day 366 exists only in leap years.
What is day 256?
Programmer’s Day. It is 13 September in a common year and 12 September in a leap year. Use Same ordinal to list that day number across years.
Can I compare several dates?
Yes. Add dates, or jump to day 100, mid-year, or Christmas. Save, CSV, and print need scripting; today’s day number stays in the HTML.