[1][2] The holy day celebrates the birth of Baháʼu'lláh, the founder of the Baháʼí Faith.

[3] Bahá'u'lláh was born on 12 November 1817 in Tehran, Iran,[4] and this holy day was instituted in the Kitáb-i-Aqdas, his book of laws, where Baháʼu'lláh first refers to four great festivals: the Festival of Ridván, the Declaration of the Báb, the birth of the Báb—who is considered to be a Manifestation of God, and who foretold the coming of Baháʼu'lláh—and the birth of Baháʼu'lláh.

[8] Baháʼís usually observe the holy day with community gatherings where prayers are shared and the birth of Baháʼu'lláh is celebrated.

Baháʼu'lláh stated that in communities where the majority of the population are Shiʻa Muslims, such as Iran, his followers should exercise caution in celebrating the twin birthdays so that they do not upset the majority of the population who are mourning during the Islamic month of Muharram.

[7] Since the Baháʼí calendar is a solar calendar, the decision to celebrate the Twin Holy Birthdays in a solar or lunar basis remains to the Universal House of Justice.