Saudi Arabian Calendar
Saudi Arabia uses the Islamic calendar which is based on a lunar year rather than the Gregorian calendar which is
based on a solar year.
A lunar month is the time between two successive new moons. The lunar year contains 12 months, but is 11 days shorter than the solar year. For the reason, the holy days gradually shift from one season to another.
Lunar year dates are derived from 622 A.D., the year of the Prophet's emigration, or Higra, from Makkah to Madinah.
The Islamic holy day is Friday. The work week in Saudi Arabia begins on Saturday and ends Thursday.