Fun fact: The arabic calendar which is based on Moon movements used to have an extra month every four(?) years to adjust the season changes. It was called Nasi

Fun fact: The arabic calendar which is based on Moon movements used to have an extra month every four(?) years to adjust the season changes. It was called Nasi' month. But after a Quran Sura published that prohibited this month Arabic calendar lost it's accuracy for seasons.[1] The Iranian Calendar that is based on sun movements was safe from this Sura because it didn't have an extra month but an extra day each five years.[2] [1] http://en.wikipedia.org/wiki/Nasi%27 http://en.wikipedia.org/wiki/Nasi%27 [2] http://en.wikipedia.org/wiki/Iranian_calendars http://en.wikipedia.org/wiki/Iranian_calendars