TEMPUSNUO

Available in English, Spanish, German and French.
Tempusnuo is a calendrical system of 13 months of exactly 28 days each — a new way of reading time that coexists with the Gregorian calendar without replacing it.
Why 13 × 28?

364 days perfectly divisible. 52 exact weeks. Each month contains exactly 4 complete weeks. The number 28 statistically aligns with documented human biological cycles. Astronomical precision equivalent to the Gregorian calendar.
The year begins on March 20, aligned with the vernal equinox. Includes Amantia (March 19) and Gratia (March 18 in leap years) — days of pause and gratitude outside the monthly count.
Included modules:

Calendar TN — 13 months with real-time Gregorian conversion · Agriculture — optimal days according to lunar biodynamic cycles · Livestock — cycles and planning in TN time · Solunar Fishing — precise solunar tables by location · Astronomy — lunar phases, events and celestial positions · Astrology 13 — zodiacal system adapted to 13 months · Menstrual cycle — complete tracking in Tempusnuo time · Daily planner with categories and events · Real-time weather by location · Daily inspirational quotes
Tempusnuo does not ask the world to change. It offers a different way to read it.

Riding Gregory's madness. — G. Jäger