Half birthday

Half birthday is so popular.
The Queen of England celebrates her birthday twice a year and some countries celebrate name day. The half birthday is the way how to celebrate twice a year like a Queen.

Half birthday celebration

In our calculator you can find HB for you, your family or friends. Also you can find HB for more than 20 000 celebrieties from our database. If someone has 20th half birthday, it means, he/she has 19 and half year. Not 20 and half. It becase we celebrate HB before birthday. E.g. new born baby celebrate his 1st HB when he/she is rouhly 6 months old and 1st birtday is after that.

Maybe you can find, that your half birday is in a special day. For example if you were born on 3nd July, your HB will be on 1st January. It will be the same as a Tom Cruise.

How to calculate halfbirtday?

The easy way

The easiest way (but not accurate)is to add 6 months to your DOB. E.g. if you were born on 1st March, your HB is on 1st September. If you do not want to calculate, just have a look on this table.

Birthday Half Birthday
January 01 July 07
February 02 August 08
March 03 September 09
April 04 October 10
May 05 November 11
June 06 December 12
July 07 January 01
August 08 February 02
September 09 March 03
October 10 April 04
November 11 May 05
December 12 June 06

The exact way

A year has 365 days. Half of it is 182.5 days. It is 182 days and a half. For that reason, if you were born in the afternoon, you will celebrate HB a diffrent day than if you were born in the morning(you celebrate on the same day). The problem is, that we do not know the hour of our birth.

Another problem is, that in a leap year with 366 days, you can celebrate HB on a diffrent day.
On this webpage, we calculate HB an easy and very precise way. We calculate it from the Tropical year (Solar year), it is time that the Sun takes to return to the same position observed from Earth. It is the time, for one full orbit of the Earth around the Sun. This time is 365.24 days or 365 days and nearly 6 hours. Now its obvious, why we need leap year every 4th year :)

Half of year is 182.62 and we can round it to 183 days. Half birthday will be 183 days from your DOB. So you don't need to worry about the time of you birthday or leap year. If you do not want to calculate it yourself, then just use our calcutator.