The 12-day Festival of Riḍván (meaning 'Paradise' in Arabic, and pronounced Rez - vaan ) is the most holy festival of the Baháʼí year. It is a joyous celebration of Baha'u'llah's public announcement, on the banks of the River Tigris in Baghdad in 1863, that He was the Promised One of all faiths. The First Day of Riḍván this year is on 21st April in the Gregorian calendar. A comprehensive new slide deck on Riḍván, together with teacher notes, can be found on the Calendar page