Online Calculator

Day of the Week Calculator

Trivia-grade utility with ISO week metadata included.

Day of the week

Sunday

Full date
July 20, 1969
Day of year / ISO week
201 / 29
Leap year?
No

How the Day of the Week Calculator works

The calculation follows the standard method used across the US — no shortcuts, no hidden assumptions. Here is exactly what happens behind the scenes:

Frequently Asked Questions

How does the Day of the Week Calculator work?

Enter your numbers above and results update instantly using standard formulas, computed entirely on your device.

Is the Day of the Week Calculator free to use?

Yes — completely free with no signup required, and it works on phones, tablets, and desktops.