Day of Year Calculator
Find the ordinal day of the year (1–365/366) for any date.
What is Day of Year?
The day of the year, or ordinal date, is a date written as a number from 1 to 365 (366 in a leap year) — March 1 is day 60 in a common year and day 61 in a leap year. It exists so dates can be compared and sorted without month tables, and it is what many scientific and accounting systems store internally.
How it works
The date is normalised to local midnight and compared with January 1 of the same year, giving the ordinal day directly. The year's length is 366 when it is divisible by 4 but not 100, or by 400 — the same leap-year rule the checker uses — and the remaining days are that length minus the day number.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Paste or type any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.