The numeric value follows JavaScript (0 = Sunday). ISO Monday-first numbering is not shown separately.

Weekday names match your selected site language.

February 29 works like any other date.

Day of Week Calculator – Find Weekday from a Date

Quickly answer what day of the week a date falls on—helpful for scheduling, historical lookups, or verifying calendars.

Date

Weekday

Choose a date.

Related tools

The date picker supplies year, month, and day; JavaScript Date resolves the weekday.

The long weekday name uses Intl.DateTimeFormat with your page locale.

JavaScript getDay() returns 0 for Sunday and 6 for Saturday.

Very old dates follow the proleptic Gregorian calendar as implemented by your browser.

Monday as 1?: The numeric value follows JavaScript (0 = Sunday). ISO Monday-first numbering is not shown separately.
Locale?: Weekday names match your selected site language.
Leap day?: February 29 works like any other date.
Privacy?: Nothing leaves this page.