Check the period as well as the number
MystLume’s personal year starts on January 1 and ends on December 31 of the selected calendar year. It does not switch on your birthday. If another source uses a birthday-to-birthday convention, a disagreement before your birthday may concern the period being described rather than an addition error.
Write the start and end dates beside the result. “Personal year 6” is incomplete as a comparison record if you do not know which year or boundary convention produced it. The personal year calculator names its calendar-year method and uses the target year you select.
Follow an October birthday through the boundary
Use October 22 as an example. For 2026, the month reduces from 10 to 1, the day reduces from 22 to 4, and the year reduces from 2026 to 10 to 1. The total is 1 + 4 + 1 = 6. Under this calculator’s rule, that result applies to January 1–December 31, 2026, including the months before October 22.
For 2025, the year component is 9. The same month and day give 1 + 4 + 9 = 14, reducing to 5. A birthday-based approach might describe a transition using the birthday as its boundary, but you need that practitioner’s exact rule before assigning dates to the two results. Do not assume every birthday-based source implements the same transition.
The tool does not blend adjacent years
Some interpretation systems describe an overlap or gradual transition. MystLume does not calculate a weighted blend of two personal years. Its displayed result follows one selected year and a stated formula. If you want to reflect on a transition between years, calculate each separately and keep the periods labelled.
This distinction is useful when checking screenshots or old notes. A saved result may use last year’s target even if the current calendar has changed. Inspect the chosen year before deciding that a calculation has become inconsistent.
Choose one convention for a journal series
If you are writing annual reflections, keep the same boundary rule across entries. Note any decision to change it, and preserve the earlier calculation. Otherwise, a sequence may appear to skip or repeat a year simply because its labels changed midway through the record.
The convention defines the arithmetic period, not a timetable for events. A January boundary does not prove that your priorities must transform overnight, and a birthday boundary does not establish that an event must wait until then. Use the theme as an organizing prompt while allowing real circumstances to set your decisions.
The personal year formula guide covers the complete calculation. The personal versus universal year comparison explains the other label often encountered beside it.
