*As noted on the Anti-Defamation League Calendar, Bahá’í, Jewish, and Islamic holidays begin at sundown the previous day and end at sundown on the date listed.
Source:
“Calendar of Observances.” Anti-Defamation League, 2019, www.adl.org/education/resources/tools-and-s.trategies/calendar-of-observances. Accessed 25 Sept. 2020

Day of the Covenant is a festival observed to commemorate Bahá’u’lláh’s appointment of His son, Abdu’l-Baha, as His successor.