Yom Kippur starts nine days after the Jewish New Year, Rosh Hashanah, and marks the end of the 10 Days of Repentance, a period of introspection in Judaism. Here is everything you need to know about the holiday and how it’s observed.

Jewish students say they face scheduling conflicts when Yom Kippur falls on a weekday. Yom Kippur begins at sundown Sunday and ends Monday evening.