Day of the Week Calculator

Enter any date to find what day of the week it falls on, plus day of year, week number and quarter.

Pick a Date

Day of Year
ISO Week Number
Quarter
Weekend or Weekday
Leap Year
Relative to Today

How This Calculator Works

Pick any date — past, present or future — and this tool instantly works out which day of the week it falls on, using the same Gregorian calendar rules used worldwide. It also shows the day's position in the year (day of year), its ISO week number, and which quarter it falls in.

Frequently Asked Questions

How do I find out what day of the week a date falls on?+

Enter any date in the calculator above and it instantly shows the day of the week (Sunday through Saturday), along with the day of the year, ISO week number, and quarter.

What is an ISO week number?+

The ISO 8601 week number counts weeks starting from the Monday of the week containing the year's first Thursday, numbered 1 through 52 or 53. It's the week-numbering standard used in business, manufacturing and many calendars worldwide.

How can I tell if a year is a leap year?+

A year is a leap year if it's divisible by 4, except years divisible by 100 unless they're also divisible by 400. For example, 2000 was a leap year, but 1900 was not.