Counting down properly
The countdown is the number of midnights between today and your next birthday, in your own time zone. On the day itself it shows 0. If your birthday was earlier this year, it counts to next year's.
Your birthday moves one weekday later each year: if it is on a Tuesday this year, it will be on a Wednesday next year, or on a Thursday if a Feb 29 falls in between. That is why a weekend birthday comes around only about two years in seven.
Worked example
| Birthday | Today | Next birthday | Days until | Turning |
|---|---|---|---|---|
| Sep 30, 1990 | Sep 29, 2026 | Wed, Sep 30, 2026 | 1 | 36 |
| Sep 28, 1990 | Sep 29, 2026 | Tue, Sep 28, 2027 | 364 | 37 |
| Feb 29, 2004 | Sep 29, 2026 | Sun, Feb 28, 2027 | 152 | 23 |
Leap-day birthdays
If you were born on February 29, your birthday is Feb 29 in leap years (2028, 2032…) and Feb 28 in the other three. Most US states use this rule for legal age too, so you can, for example, get your driver's license on Feb 28.
What people ask next
- How old am I, exactly? for years, months and days.
- Days between two dates for any other countdown: a trip, a due date, a deadline.
How we calculate
Days until = next birthday date − today. If today is your birthday, the answer is 0.
- Feb 29 birthdays fall on Feb 28 in non-leap years.
Every formula is checked by automated tests. Methodology · Updated