These Bahá’í holy days begin at sunset the first day and end at sundown the second day. They land on different days every year based on lunar calculations or the solar calendar starting with the Spring Equinox. The Festivals of the Twin Birthdays or the Twin Holy Birthdays celebrate the births of two central figures of the Baháʼí Faith. It is a joyous event that begins with prayers and devotional readings and develops into some kind of festive social gathering, either at home or in a place of worship.  These are two of the nine holy days of the year when work is suspended.