How to use it
- Enter the date of birth as YYYY-MM-DD.
- The second date is the day to search from. Change it to look ahead or back.
- Read the next half birthday, the days to wait and the age on that day. The list below shows the following five.
How it works
The half birthday after k whole years is the date of birth moved forward by 12 × k + 6 calendar months. The first of these on or after the search date is the answer. When the day of the month does not exist in the target month, the month’s last day is used.
Worked example
Born on 15 May 1990, searching from 3 November 2026: the 36th year and six months ends on Sunday, 15 November 2026. That is 12 days after 3 November, and the person is then 36 years and 6 months old.
Ideas
- Celebrate children’s half birthdays, which are popular for those born near a holiday.
- Use it for pets, when the exact birthday is known.
- For the exact age on any day, use the age calculator.