Estehlal Headquarters (Persian: ستاد استهلال, romanised: Setade Estehlal) is an organization and command post based in Iran,[1][2][3] that deploys groups to monitor the sky and identify the crescent of the moon[4][5] on the first night(s)[6] of the Lunar month,[7] as per the Islamic tradition of Estehlal.

[16][17] Along with Iran's supreme leader,[18] other Shia Marja' al-Taqlids have paid heed to the practice of Estehlal.

Among them is Seyyed Ali Sistani, who established a related center in the city of Qom, and Mohammad Mohammadi Reishahri (the trusteeship of Shah Abdol-Azim Shrine), who established a similar center in Tehran.

[19] The significance of Estehlal[20][21][22] pertains to the observation of the Moon's crescent, referred to as Hilal.

Estehlal headquarters was established to clarify the existing disparities between similar organizations regarding the discernment of the beginning of lunar months;[23][24][25] i.e. the Qamari months such as Ramadan, Shawwal, etc.