Find the weekday for any date, plus its day of the year and ISO week number.
Runs entirely in your browser.
Find What Day of the Week a Date Falls On
Date
About Day of the Week Calculator
This gives the weekday for any date, along with two numbers that often matter alongside it: the day of the year (1-366) and the ISO-8601 week number.
ISO weeks start on Monday, and week 1 is the week containing the first Thursday of January. That means the first days of January can belong to week 52 or 53 of the previous year - a detail worth knowing before you build reporting on week numbers.
Other Date Tools
- Date Calculator — difference, arithmetic and age on one page
- Age Calculator — exact age and days to the next birthday
- Date Difference — the span between two dates
- Add or Subtract Days — date arithmetic
- Leap Year Checker — is a year a leap year, and why
- Unix Timestamp — epoch seconds to and from a date
- Time Converter — seconds, minutes, hours, days, weeks