How to Use It
Know Your Day Number
Count from March 20 (Day 1). Today's Gregorian date has a Prime Calendar equivalent. Approximately one in five days is prime. Use the calculator below.
Mark the Eight Gates
These are the year's structural moments — days of transition, threshold, and heightened potential. Give them conscious attention. Seven of eight fall on prime days.
Notice the Twin Prime Windows
Twin primes (pairs like 41–43, 137–139, 227–229) create transitional portals. Several coincide exactly with ancient festival windows.
Track the Five Seasons
Five periods of 73 days each, beginning at the Equinox. More natural than the Gregorian four — derived from the year's own prime factorization.
Watch the Moon
Every 19 years (the Metonic cycle — 19 is prime), the lunar and solar calendars resynchronize. Note when Full or New Moon coincides with a prime day.
Find Your Day
What Day Is It?
The Eight Gates
Mark these days with conscious attention. They are the year's turning points — moments when the geometry shifts.
| Gate | Day | Date | Name | Practice |
|---|---|---|---|---|
| 1 | 1 | Mar 20 | Opening | Set intention for the year |
| 2 | 43 | May 1 | Fire | Light a fire. Begin what you've been waiting to begin. |
| 3 | 97 | Jun 24 | Light Peak | Celebrate maximum light. Notice what's fully visible. |
| 4 | 137 | Aug 3 | Axis | The Hidden Gate. Silence, fasting, deep attention. |
| 5 | 149 | Aug 15 | Harvest | First fruits. Gather what's ready. |
| 6 | 227 | Nov 1 | Shadow | Honor the dead. Face what's hidden. |
| 7 | 277 | Dec 21 | Dark Peak | Longest night. Light returns from here. |
| 8 | 359 | Mar 13 | Return | Completion. The year closes its cycle. |
Twin Prime Windows
Twin primes are pairs of primes separated by exactly 2 — the closest primes can get. In the calendar, they form brief transitional portals:
| Days | Dates | Window |
|---|---|---|
| 41–43 | Apr 29 – May 1 | Walpurgis → Beltane |
| 71–73 | May 29 – May 31 | Spring closes |
| 137–139 | Aug 3 – Aug 5 | The Axis Window |
| 179–181 | Sep 14 – Sep 16 | Harvest deepens |
| 227–229 | Nov 1 – Nov 3 | The Veil of Samhain |
| 281–283 | Dec 25 – Dec 27 | Christmas Rebirth |
| 347–349 | Mar 1 – Mar 3 | Year's final window |
The Five Seasons
365 = 5 × 73. The year naturally divides into five seasons of 73 days each:
Opening (Mar 20 – May 31): Emergence. Seeds planted. The year awakens.
Rise (Jun 1 – Aug 12): Ascent toward fullness. Maximum light. Day 137 falls here.
Expansion (Aug 13 – Oct 24): Harvest and abundance. Fruits gathered. Peak expression.
Descent (Oct 25 – Jan 5): Release and return. Darkness grows. Samhain and Solstice.
Integration (Jan 6 – Mar 19): Rest and consolidation. The year prepares for renewal.