Millions of Iranians are holding ceremonies to celebrate the anniversary of the birthday of the twelfth and last Shia Imam, Imam Mahdi (Peace Be Upon Him).

Mid-Sha’ban, the fifteenth day of the eighth month of the lunar calendar, marks the joyous occasion.

Imam Mahdi, known as the Savior or Messiah, was born almost 1,200 years ago.

Every year, millions of Muslims around the world hold festivities to honor the event.

In Iran, people decorate and light up streets and gather inside mosques and other religious sites nationwide to celebrate the auspicious occasion. 

In Shia eschatology, Imam Mahdi is the prophesied redeemer, who will revive peace, administer justice and rid the world of evil. 

The occasion which falls on June 3rd this year, is a national holiday in Iran.