Day of the Week Calculator

Which day of the week were you born on? What weekday will a holiday fall on next year? Enter any date to find out, together with the day of the year and the week number.

How weekdays repeat

A common year has 365 days, which is 52 weeks plus 1 day, so a date usually moves forward one weekday each year: if your birthday is on a Tuesday this year, it will be on a Wednesday next year. After February 29 in a leap year, the jump is two weekdays. The whole pattern of the Gregorian calendar repeats exactly every 400 years.

Leap years

A year is a leap year if it is divisible by 4, except century years, which must be divisible by 400. So 2000 was a leap year but 1900 and 2100 are not. The calculator shows whether the chosen date's year is a leap year.

Day of the year

The day of the year (sometimes called the ordinal date or, loosely, the "Julian date") counts from 1 on January 1 to 365, or 366 on December 31 of a leap year. It is used in manufacturing date codes, food labelling and scientific data.