Before the birthday
- Input
- 15 Jun, 2026-03-10
- Expected output
- 4 / 3
Calendar year / birthday year. The birthday year still uses 2025: 6 + 6 + 9 = 21, which reduces to 3.
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when does personal year change
Between January and your birthday, the personal year can be one number or another, depending on the school. The tool lets you switch the convention under Options and shows the exact period of each personal year.
Calendar year / birthday year. The birthday year still uses 2025: 6 + 6 + 9 = 21, which reduces to 3.
Birthday year and its period. Personal year 3 closes on this day.
Birthday year and its period. The two conventions coincide from this day until December 31.
Year used in the math / 2026 birthday date. In 2024, a leap year, the birthday is back on February 29.
Reduce the birth day, the birth month and the reference year to one digit each, add the three and reduce again. Example: June 15 in 2026 becomes 6 (1+5), 6 and 1 (2+0+2+6 = 10, then 1), a sum of 13, which reduces to 4. The result is personal year 4.
Neither is the only correct one: they are choices of different schools. The tool opens on the calendar year, the more common one on websites, and lets you switch to the birthday year under Options.
No. The personal month adds the personal year to the calendar month number, so it changes on the 1st of each month. Only the personal year, the basis of that sum, depends on the convention.
On a given date, yes, it can change by one step, between January and the birthday. Outside that stretch both give the same number, and the cycle keeps climbing one at a time.
All calculation happens in your browser. No date is sent to a server.