Day of the Week Calculator

This weekday calculator instantly determines the day of the week for any date — past, present, or future. Whether you're curious about a birthday, a historical event, or planning ahead, just enter a date.

How to Use the Calculator

1. Enter the Date: Input the year, month, and day in the corresponding fields. For example, enter 2020, 2, and 1 to check February 1st, 2020.
2. Get Your Result: Click the Calculate button to instantly see which day of the week the date falls on — Monday, Tuesday, Wednesday, and so on.

Fun Facts About Days of the Week

What Is the First Day of the Week?

The seven-day week is a global standard, but different regions define the first day differently. ISO 8601, the international standard, starts the week on Monday — common in Europe. In the United States, Canada, and Japan, Sunday is often considered the first day. Either way, the weekly cycle always spans seven days.

Where Do the Names Come From?

The English names for days of the week blend Roman and Norse mythology. Sunday and Monday honor the Sun and Moon. The remaining days come from mythology: Tuesday from Tyr (Norse god of war), Wednesday from Odin (chief Norse god), Thursday from Thor (god of thunder), Friday from Frigg (goddess of love), and Saturday from Saturn (Roman god of agriculture).