Day of Week Calculator · Practical guide
What Day of the Week Was I Born?
Enter your birthdate and instantly see whether you arrived on a Monday, a Friday, or any other day.
At a glance
The Quick Answer
Select your birthdate above and the calculator names the weekday instantly. For example, someone born on June 15, 1990 arrived on a Friday, and September 11, 2001 — a date many people ask about — was a Tuesday. The tool handles any date, so it works for parents, grandparents, and historical figures too.
Interactive tool
Day of Week Calculator
Enter your own values, then compare the result with the examples below.
Result
Why Your Birthday Shifts Each Year
A normal year has 365 days — 52 weeks plus 1 day — so your birthday moves forward one weekday annually. After a February 29 falls between birthdays, it jumps two. Born Friday, June 15, 1990? Your birthday fell on Saturday in 1991, then leapt straight to Monday in 1992 because February 29, 1992 passed in between, and landed on Tuesday in 1993.
Birthdays and Leap Years
- February 29 birthdays exist only in leap years — divisible by 4, except century years not divisible by 400 — so 2000 had one but 1900 did not.
- Leap-day babies typically celebrate on February 28 or March 1 in off years.
- The calculator applies these rules automatically, so February 29, 2000 correctly shows as a Tuesday.
Fun Ways People Use This
- Settling the classic "Monday's child" nursery-rhyme question.
- Checking whether a milestone birthday — 30th, 50th — lands on a weekend for party planning.
- Verifying family stories: was Grandma really born on a Sunday?
- Building trivia: find which weekday you share with a famous figure born the same day.
Frequently Asked Questions
How accurate is the result for old birthdates?
The calculator uses the proleptic Gregorian calendar, which is exact for any date after the US adopted it in 1752 and a mathematical extension before that. Birthdates in the 1900s are fully reliable.
What if I was born on February 29?
Enter it normally — the tool accepts February 29 in leap years only, and will show the correct weekday, such as Tuesday for February 29, 2000.
Can I check someone else's birthdate?
Yes. Any date works — children, parents, historical figures. There is no limit on how far back you can go.
Why does my birthday land on a different weekday each year?
Because 365 days is 52 weeks plus 1 day, the date advances one weekday per year — two after a leap day passes between birthdays.