The Birth of the Báb is a Bahá'í holy day commemorating the birth of Siyyid 'Ali-Muhammad, the founder of the Bábí Faith and forerunner of Bahá'u'lláh, who was born in 1819 in Shiraz, Persia . It is the first of the "Twin Holy Birthdays" (followed by the Birth of Bahá'u'lláh), and its date follows a lunar calculation, falling in 2026 on November 10 . Bahá'ís observe the day by suspending work and gathering for devotional meetings, readings, and fellowship, honoring the Báb's mission to herald the imminent coming of "Him Whom God shall make manifest" .