Day of the Week Calculator
Find the day of the week for any date, plus the day of the year and ISO week number.
Enter your values and press Calculate.
How to use the Day of the Week calculator
Find the day of the week for any date, plus the day of the year and ISO week number. Enter your values above and press Calculate; the result appears instantly, and the formula used is shown below so you can check the working.
Formula
Computed from the proleptic Gregorian calendar. ISO weeks start on Monday; week 1 contains the year’s first Thursday.
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