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Day of the Week Calculator

Look up the day of the week for any date.

Find the day of the week for any past or future date, plus the day-of-year, ISO week number, and how far the date is from today.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

Uses the Gregorian calendar. ISO week 01 is the week containing the first Thursday of the year.

In depth

Find the day of the week for any past or future date, plus the day-of-year, ISO week number, and how far the date is from today.