which event marks the start of the islamic calendar
Islamic calendar The Islamic calendar employs the Hijri era whose epoch was retrospectively established as the Islamic New Year of AD 622. During that year, Muhammad and his followers migrated from Mecca to Yathrib (now Medina) and established the first Muslim community (ummah), an event commemorated as the Hijra. In the West, dates in this era are usually denoted AH (Latin: Anno Hegirae, "in the year of the Hijra") in parallel with the Christian (AD) and Jewish eras (AM). In Muslim countries, it is also sometimes denoted as H[1] from its Arabic form ( سَنة هِجْريّة, abbreviated هـ). In English, years prior to the Hijra are reckoned as BH ("Before the Hijra").[2]
Hanukkah The dates of Hanukkah are determined by the Hebrew calendar. Hanukkah begins at the 25th day of Kislev and concludes on the 2nd or 3rd day of Tevet (Kislev can have 29 or 30 days). The Jewish day begins at sunset. Hanukkah begins at sunset of the date listed.