In the Kitáb-i-Aqdas, written during 1873, Baháʼu’lláh ordains Ridván as one of two “Most Great Festivals”, along with the Declaration of the Báb. He then specified the first, ninth, and twelfth days to be holy days; these days mark the days of Baháʼu’lláh’s arrival, the arrival of his family and their departure from the Ridván garden, respectively.
The Festival of Ridván is observed according to the Baháʼí calendar, and begins on the thirty-second day of the Baháʼí year, which falls on 20 or 21 April. The festival properly starts at two hours before sunset on that day, which symbolises the time that Baháʼu’lláh entered the garden. On the first, ninth, and twelfth days, which are Baháʼí Holy Days, work is prohibited. Currently, the three holy days are usually observed with a community gathering where prayers are shared, followed by a celebration.
The time that Baháʼu’lláh spent at the Garden of Ridván in April 1863, and the associated festival and celebration, has a very large significance for Baháʼís. Baháʼu’lláh calls it one of two “Most Great Festivals” and describes the first day as “the Day of supreme felicity” and he then describes the Garden of Ridvan as “the Spot from which He shed upon the whole of creation the splendours of his Name, the All-Merciful”.
The festival is significant because of Baháʼu’lláh’s private declaration to a few followers that he was “Him Whom God shall make manifest” and a Manifestation of God, and thus it forms the beginning point of the Baháʼí Faith, as distinct from the Babi religion. It is also significant because Baháʼu’lláh left his house in Baghdad, which he designated the “Most Great House”, to enter the Garden of Ridván. Baháʼu’lláh compares this move from the Most Great House to the Garden of Ridván to Muhammad‘s travel from Mecca to Medina.
Furthermore, during Baháʼu’lláh’s first day in the garden, he made three further announcements: (1) abrogating religious war, which was permitted under certain conditions in Islam and the Bábí faith; (2) that there would not be another Manifestation of God for another 1,000 years; and (3) that all the names of God were fully manifest in all things. These statements appear in a text written some years after 1863, which has been included in the compilation Days of Remembrance (section 9). Nader Saiedi states that these three principles are “affirmed, expounded, and institutionalized” in Baháʼu’lláh’s Kitab-i-Aqdas, which was completed in 1873.