Birthday Calculator
Enter your date of birth to find the day of the week you were born and count down to your next birthday.
What this calculator does
The Birthday Calculator finds what day of the week you were born on, counts down the days until your next birthday, and shows the age you’re about to turn.
How the calculation works
The calculator builds a date object from your birth year, month, and day, and reads off its weekday directly from the calendar system, which is exact for any real date. Your current age is found by comparing today’s date to your birthday this year, and the next birthday is simply the closest upcoming occurrence of your birth month and day, rolling into next year if this year’s has already passed.
This tool is for general and celebratory use, such as fun facts or planning a birthday celebration. It is not intended for legal age verification.