What day is it? Calculator
Every calendar date falls on one of the seven days of the week, and that day can be worked out for any date in the past or future. This perpetual calendar calculator tells you which day of the week any date was or will be — your birth, a birthday, or a famous historical event. Just enter a past or future date and it will tell you the weekday.
What day is it? Calculator
Example weekday calculations
Practical information about our “What day is it?” Calculator
- Many people want to know on which day of the week a date fell. If you enter an arbitrary date, our perpetual calendar calculator tells you whether it fell on Monday, Tuesday, Wednesday, Thursday, Friday, Saturday or Sunday.
- Did you know that Independence Day ( July 4, 1776, USA ) fell on Friday? Our calculator may be used with any arbitrary date to check on which day it fell.
- Which calendar is used by the calculator? We use the Gregorian calendar which was introduced by Pope Gregory XIII. It was introduced on 4 October 1582 and the next day was 15 October 1582 because some days had to be omitted for the adoption of the new calendar. That is why our perpetual calendar calculator works only for days after the introduction of the Gregorian calendar (15 October 1582).
This calculator provides accurate answers to the following questions:
- What day was it when I was born?
- What day was it when we first met?
- What day is it today?
- What day was it yesterday?
- What day will it be tomorrow?
- What day was it on ... date?
- What day will it be on ... date?
If you would like to know what day of the week a past or future date was or will be, simply enter the date and we will show you the result immediately.
Frequently asked questions
How do I find what day of the week a date was?
Enter any date and the calculator returns the weekday, using the rules of the Gregorian calendar for past and future dates alike.
What day of the week was I born?
Enter your date of birth and the calculator instantly shows the weekday you were born on.
Can the calculator handle future dates?
Yes. It works as a perpetual calendar, so you can find the weekday of any future date, such as a birthday or anniversary.
How is the day of the week calculated?
The calculator applies the Gregorian calendar rules, including leap years, to map any date to one of the seven weekdays. Algorithms such as the congruence of Zeller do the same by hand.
Does it account for leap years?
Yes. Leap years are fully accounted for, so weekday results stay correct across century and leap-year boundaries.