Date & time Birthdays

What day was I born

Date of birth

Day of the week —

Gregorian calendar

About that date

The full date —

Day of the year —

ISO week —

Quarter —

Birthstone —

Leap year —

Unix timestamp —

Note Enter a date

The calendar repeats every 400 years

Any date maps to exactly one weekday. 15 June 1990 was a Friday. The Gregorian calendar repeats on a 400-year cycle, so the same date in 2390 will fall on a Friday too.

How to find the day you were born

1 Enter your date of birth.

2 Read the weekday.

3 The day of the year, week number and birthstone are shown too.

4 It works for any Gregorian date.

The 400-year cycle exists because the Gregorian leap rule — every four years, except centuries not divisible by 400 — produces exactly 146,097 days, which happens to be a whole number of weeks. That is not a coincidence in the calendar design but a happy accident of the arithmetic, and it means the entire pattern of dates and weekdays repeats identically every four centuries.

Questions

What day of the week was I born? −

Enter your date of birth and it is shown at the top.

Does the calendar repeat? +

Does it work for old dates? +

What is my birthstone? +

What is the day of the year? +

Was this tool any good?

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