Three layers, one arithmetic
All three timing numbers come from the same operation: take your birth month and day, add a unit of time, reduce. The unit changes; the method does not.
| Layer | Formula | Describes |
|---|---|---|
| Personal Year | birth month + birth day + current year | The theme of a roughly twelve-month chapter |
| Personal Month | Personal Year + calendar month number | The texture of the next few weeks |
| Personal Day | Personal Month + date | The tone of a single day |
Note what is not in there: your birth year. Personal Year is not tied to your age or your Life Path — two people born on the same calendar day are in the same Personal Year regardless of how many decades separate them.
Worked example: born 14 March, in 2026
Month = 3. Day = 14 → 1 + 4 = 5. Year 2026 → 2 + 0 + 2 + 6 = 10 → 1.
3 + 5 + 1 = 9. This person is in a Personal Year 9 for 2026 — a closing, clearing, letting-go year.
Their twelve Personal Months follow mechanically:
| Month | Sum | Personal Month | Character |
|---|---|---|---|
| January | 9 + 1 = 10 | 1 | A false start — beginnings inside an ending year |
| February | 9 + 2 = 11 | 2 | Waiting, cooperation, other people's pace |
| March | 9 + 3 = 12 | 3 | Expression returns; birthday month here |
| April | 9 + 4 = 13 | 4 | Admin, repair, the unglamorous middle |
| May | 9 + 5 = 14 | 5 | Restlessness, travel, disruption |
| June | 9 + 6 = 15 | 6 | Home, family, obligations surface |
| July | 9 + 7 = 16 | 7 | Withdrawal and review — the year's most useful month |
| August | 9 + 8 = 17 | 8 | Money and authority questions get answered |
| September | 9 + 9 = 18 | 9 | The double-9 month; the heaviest clearing |
| October | 9 + 10 = 19 | 1 | The next chapter becomes visible |
| November | 9 + 11 = 20 | 2 | Slow down; nothing forces well here |
| December | 9 + 12 = 21 | 3 | Lightness returns before the new cycle |
Personal Days work the same way from the month figure: in that July (Personal Month 7), the 9th is 7 + 9 = 16 → 7, a doubled 7 day.
The disagreement: 1 January or your birthday?
This is the live argument in Personal Year practice, and most sites pretend it does not exist.
- Calendar-year camp: the Personal Year changes at midnight on 1 January, because the calendar year is the input to the formula. Change the input, change the output.
- Birthday camp: the Personal Year runs birthday to birthday, because the cycle is personal and should start on the personal date. Under this reading, January to your birthday is a transition period sharing qualities of both years.
Our position: the calendar-year boundary, with a transition acknowledged. The arithmetic uses the calendar year, so the clean reading is that the number changes when that value changes. But the birthday camp is describing something real — people consistently report that a new Personal Year does not feel fully arrived until after their birthday, and the closer your birthday is to December, the longer that lag runs.
In practice: from 1 January, read the new year's theme as the operative one, and treat the stretch up to your birthday as the old year finishing its sentence. This site's Personal Year pages and the Personal Month calculator both use the calendar-year boundary.
Which layer to actually use
An honest ranking, based on which produces usable decisions:
- Personal Year — by a wide margin the most useful. It operates at the scale real decisions happen at: change jobs, move, commit, rest. A 1 year and a 9 year genuinely suggest opposite postures.
- Personal Month — useful for sequencing within the year. Knowing July is your 7 month is a reason to put the strategy work there instead of in the 5 month.
- Personal Day — the least useful, and the one most likely to become superstition. A single day's number is a weak signal drowned out by everything else in your life. We include it for completeness, not because we think anyone should plan around it.
Three mistakes that produce wrong numbers
- Using your birth year. The formula takes the current year. Including your birth year gives you your Life Path again, not a timing number.
- Reducing the date wrongly. Reduce the day of birth to a single digit here — the master-number rule that applies to Life Path is generally not carried into Personal Year practice, which is why a birth day of 11 is treated as 2 in this formula by most practitioners.
- Treating a 9 year as a bad year. It is a completion year. Things end in it because they were finishing anyway. Starting a major venture in a 9 year is the mistake, not experiencing endings.
Each Personal Year has its own page with the full reading: 1, 2, 3, 4, 5, 6, 7, 8, 9.