Half Birthday Calculator
Pick a birthday to find the date six months later, and how long until it comes around.
Your half birthday is
six months after your birthday
Choose the month and day to find it.
Marking it with a present? Answer six quick questions and Nova, our gift finder, suggests personalized gifts that fit the person.
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How a half birthday is worked out
Take the birthday, keep the day of the month and move the month forward by six. January becomes July, February becomes August, and so on around the year. That is all there is to it for most dates.
The exceptions are birthdays near the end of a month whose opposite month is shorter. There the half birthday falls on the last day of that month. If you would rather celebrate on the first day of the next month, nobody is going to stop you.
Half birthdays by month
| Birthday in | Half birthday in |
|---|---|
| January | July |
| February | August |
| March | September |
| April | October |
| May | November |
| June | December |
| July | January |
| August | February |
| September | March |
| October | April |
| November | May |
| December | June |
Counting down to the real one instead? Use the birthday countdown.
Questions people ask
When is my half birthday?
Your half birthday is the same day of the month, six months after your birthday. A birthday on March 12 has its half birthday on September 12. Pick your birthday above to see the date and how many days away it is.
What if that day does not exist six months later?
A few birthdays have no matching day: August 29, 30 and 31 point at the end of February, and March, May, October and December 31 point at months with 30 days. This calculator uses the last day of that month, so August 31 gives February 28, or February 29 in a leap year.
Is a half birthday exactly half a year?
Not to the day. Six calendar months can be anywhere from 181 to 184 days, and half of a 365-day year is 182.5. Counting by calendar months is the usual convention because it gives a date that is easy to remember.
Why do people celebrate half birthdays?
Mostly because the real birthday is badly placed: on or near a major holiday, in the middle of summer vacation when friends are away, or in the depths of winter. A half birthday moves the party to a better time of year. Schools also use them so that kids with summer birthdays get a turn in class.
More date tools
- Anniversary CalculatorHow long you have been together, your next anniversary and every milestone on the way.
- Birthday CountdownDays, hours, minutes and seconds until the next birthday.
- Days Until CalculatorCount the days, weeks and working days until any date.