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Day of Year Calculator

Find the ordinal day number, week number, quarter and how much of the year has elapsed.

The day of the year, or ordinal date, counts from 1 on 1 January to 365 or 366 on 31 December. This calculator also gives the ISO week number, the quarter, the Julian Day Number used in astronomy, the Unix timestamp, and the percentage of the year elapsed.

Runs in your browser
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

What is an ISO week number?

A week numbering where week 1 is the one containing the year's first Thursday. It means early January can fall in week 52 of the previous year — which surprises people but keeps every week a full seven days.

How to use the day of year calculator

  1. 1Enter or paste your date.
  2. 2The result appears immediately — copy or download it.

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Put the working day of year calculator on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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