Annual Holidays in Iran:

The official weekend holiday in Iran is Friday. Iranian religious holidays are based on lunar system while the Persian calendar is based on Solar system. Religious holidays are subject to change depending upon the official sighting of the moon. Generally in the below-mentioned banking holidays which are mostly religious, all the historical sites and museums are not working.
Note: In Iran we have some public holidays that are only bank holidays and tourists sites are open but during the dates in red, all sites are closed. 

11 FebRevolution Day
13 MarMartyrdom of Fatima
19 MarOil Nationalization Day
20 MarNorooz (Persian New Year)
21 MarNorooz Holiday
22 MarNorooz Holiday
23 MarNorooz Holiday
30 MarBirthday of Imam Ali
14 AprProphet’s Ascension
01 MayImam Mahdi’s birthday
4 Jun Demise of Imam Khomeini
5 JunMartyrdom of Imam Ali
15 & 16 junEid-e-Fetr (End of Ramadan)
09 JulMartyrdom of Imam Sadeq
22 AugEid-e-Ghorban (Feast of Sacrifice)
30 AugEid-al-Ghadir
20 SepTassoua
21 SepAshura
31 OctArbaeen
06 NovThe Murder And Matrydom of prophet Mohammad
09 NovMartyrdom of Imam Reza
26 NovBirthday of Muhammad and Imam Sadeq