Time & Date

Time Until Birthday Calculator

Enter your birth date to find exactly how many days remain until your next birthday, and what age you'll be turning.

Your birthday

Days until your birthday
Enter your birth date to calculate.

How the Time Until Birthday formula works

Finding the next occurrence of a birth month and day:

Next birthday = birth month/day in the current year (or next year, if that date has already passed)
Days remaining = Next birthday − Today

Step-by-step calculation

  1. Apply the birth month and day to the current year to get this year's birthday date.
  2. If that date has already passed this year, use next year's date instead.
  3. Subtract today's date from that upcoming birthday date to find days remaining.

Worked example

A birthday of November 3, checked on August 4: since November 3 hasn't occurred yet this year, the next birthday is this coming November 3 — about 91 days away.

Frequently asked questions

What happens if today is my birthday?

The calculator will show 0 days remaining, and the 'next' birthday shown will be exactly one year from today.

How does this handle a birthday on February 29 (leap day)?

In non-leap years, the calculator treats the nearest equivalent date (commonly February 28 or March 1, depending on convention) as the recognized birthday, since February 29 doesn't exist on the calendar that year.