Secular perpetual calendar
![[[Franck Muller Aeternitas 4]]\\ with **secular perpetual calendar** (click to enlarge!)](/lib/exe/fetch.php?tok=1d1db7&media=https%3A%2F%2Fwww.uhren-wiki.com%2Fimages%2FFranck_Muller_Aeternitas_4.jpg "[[Franck Muller Aeternitas 4]]\\ with **secular perpetual calendar** (click to enlarge!)")
Franck Muller Aeternitas 4
with secular perpetual calendar
© Franck Muller
Calendar function
Rare variant of the perpetual calendar, which also takes into account the long-term exclusion rules for determining the leap years partially
- 100s rule = 1900, 2100, 2200, … are no leap years, or even completely
- 400s rule = 2000, 2400, … again are leap years.