====== Secular perpetual calendar ======
{{wst>image_cl|Franck Muller|Aeternitas 4|[[Franck Muller Aeternitas 4]]\\ with **secular perpetual calendar**|250px}}

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.


{{tag>Terms}}