On the third day of the month of Jumada al-Thani, Shia Muslims commemorate the death anniversary of Muhammad's daughter Fatimah.
Martyrdom of Fatimah is a public holiday in Iran because Shia Islam is the official religion in this country.
Fatimah Zahra was the youngest daughter of the Islamic prophet Muhammad and his first wife Khadijah.
She is greatly venerated by all the Muslims because she was very close to her father and offered him support in his difficulties.
She also is the only member of the prophet's family to have given him descendants known as the Fatimids.
Fatimah's husband and two sons are important figures of Islam.
She was married to Muhammad's cousin Ali, who was the first young male to accept Islam.
Their two sons Hasan and Husayn are the second and third Imams of Shia Islam correspondingly.
Sunni Muslims consider them important figures as well.
Fatimah died in 632, several months after her father's death.
Most Shia Muslims believe that she was killed by caliph Umar, which makes her a martyr.
The anniversary of her martyrdom is marked every year by mourning ceremonies and processions.
Ceremonies are held for twenty days, but only 3 Jumada al-Thani is declared a public holiday in Iran.