When is my half birthday?
Pick the month and day of any birthday, yours or someone else's. You'll see the half birthday, six months later, and how many days until the next one. Add the year to see the age they turn.
How the half birthday is worked out
- The half birthday is six months after the birthday, on the same day of the month: March 14 gives September 14, and October 2 gives April 2.
- When that month is shorter, the half birthday is its last day. August 31 gives February 28, or February 29 in a leap year. March 31, May 31, October 31 and December 31 give the 30th.
- A February 29 birthday has its half birthday on August 29 every year.
- The days are counted from today's date on your device. A half birthday tomorrow is 1 day away.
- With a year, the age is the whole years on the half birthday, and a half.
Everything is worked out in your browser. The date you pick is not sent anywhere or saved, unless you save it with the form above.
Counting down to the birthday itself? See how many days until a birthday.
Frequently asked questions
How is a half birthday worked out?
It is six months after the birthday, on the same day of the month. A March 14 birthday has its half birthday on September 14.
What if the birthday is on the 29th, 30th or 31st?
When the month six months later has no such day, the half birthday is that month's last day. August 31 gives February 28, or February 29 in a leap year, and March 31 gives September 30. A February 29 birthday has its half birthday on August 29.
Why not count 182 days instead?
Some people count half of 365 days instead, which can land a day or two away from the date here. This page counts six months on the calendar, so the half birthday keeps the same date each year, apart from February 29 in a leap year.
Can I get a reminder before the birthday?
Yes. Save the birthday with the form under the answer, and Greetigo emails you the day before the birthday, every year, with a message ready. It is free for up to 10 saved dates.