In Iran, working days are Saturday to Thursday. Friday is the only official weekend holiday, but some companies are off or work half day on Thursdays. Iran's official holidays are being extracted from two calendar systems :
National Official Calendar is a Solar calendar (1 year = 365 days) and is easily comparable to Gregorian (international) calendar. نوروز “Nowrooz” Persian New Year, the celebration of Iranian New Year, starts on March 20 and is considered the most important holiday in Iran. Festivities take place over 12 days and usually involve the cleaning of homes, giving monetary gifts and the visiting of relatives. The last day of the Nowrooz is called سیزده بدر “seezde bedar" .Iranians spend سیزده بدر “seezde bedar" the thirteenth day of the New Year outdoor .
Islamic Calendar is a Lunar Calendar (1 year=355 days) which causes the religious holidays move along the solar year.