Enter your full birth date to find the day of the week you were born. The calculator uses the Gregorian calendar. For example, September 9, 2000 was a Saturday.
Find your birth weekday
Enter your complete birth date. The initial date is a worked example.
September 9, 2000
SaturdayThis is the weekday of the entered date. Birth time and location are not required.
Your dates stay in this page. This calculator does not send or save them.
How to find the day of the week you were born
Enter your birth month, day, and year. The birth weekday calculator returns Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday for that complete date.
The year matters because the same month and day can fall on different weekdays. September 9, 2000 was Saturday. September 9, 2001 was Sunday.
Your entries stay in your browser. The calculation needs no birth time or location.
Leap years and valid birth dates
The tool accepts valid Gregorian dates from 1600 through 9999. It rejects dates such as April 31 and February 29 in a common year.
February 29, 2000 was a Tuesday. Its weekday comes from that actual date. You do not need to choose a February 28 or March 1 anniversary.
The U.S. Naval Observatory leap-year guide gives the Gregorian rule. Years divisible by four are leap years, except century years not divisible by 400. Thus, 2000 was a leap year, and 2100 will be a common year.
Calendar dates, time zones, and older records
Use the calendar date recorded where you were born. The tool calculates from the entered date only. Changing your device’s time zone does not change its weekday.
The tool applies Gregorian rules throughout its date range. It does not convert dates from the Julian calendar or other calendars.
The U.S. Naval Observatory calendar notes explain that countries adopted the Gregorian calendar at different times. Check which calendar an older birth record uses before entering its date.
Future dates and your next birthday
You can enter a future date to check its weekday. The tool labels a birth date after the comparison date as a hypothetical example.
The comparison date starts with your device’s local date. You can change it. This comparison does not change the weekday calculation.
To find the weekday of your next birthday, enter that future month, day, and year. That result describes the future date.
Your birth weekday remains the weekday of your original birth date. A birthday anniversary can fall on another weekday.
Which weekday has the most births?
A personal birth weekday tells you when one date occurred. Birth frequency requires records for a stated population and period.
Our weekday and weekend birth study compares U.S. SSA birth records from 2000–2014. It answers which weekdays had more recorded births in that period.
Use the birthday rarity checker to compare your month and day with historical U.S. birth counts. For other calendar dates, try the golden birthday calculator or half-birthday calculator.
The methodology explains the checker’s records and ranking rules. For other celebration rules, compare diamond and platinum birthday meanings.