13. The most important holiday in Judaism is Yom Kippur, the day of atonement. What do Jews give up for a day to atone for their sins?
From Quiz Jewish Holidays
Answer:
Food
Yom Kippur is a day of fasting. It actually starts at sundown one day and ends at sundown the next. Thus by eating just before sundown before it starts and then again just after it ends, only two meals (breakfast and lunch) are actually missed.
The way the Jewish calendar works, Yom Kippur can never start on a Monday, Thursday, or Saturday night. I'm not sure why it doesn't start on Monday, but avoiding the other two days makes sense in accordance with the rules of Sabbath. If it started on Thursday, it would end on Friday night which would mean that the big meal to end the fast would have to be prepared before Thursday in order to avoid cooking on either Yom Kippur or the Sabbath. Likewise, if it started on Saturday night, it would be difficult to cook a sizable meal to prepare for the fast due to it starting at the end of the Sabbath.