Islam as a
religion does not have a scripturally sanctioned calendar, nor is there a Sunnah
or a Prophetic tradition suggesting one.
In Pre-Islamic Arabia there was a traditional 12-month calendar based on
lunar phases with an intercalary month, referred to as an-nasī,ʾ ‘postponing’. The purpose of the intercalary month was to
synchronize the lunar calendar with the solar cycle in order to achieve a more
consistent relationship between the months and the seasons of th...