Yom Kippur is probably the most important holiday of the Jewish year. The name "Yom Kippur" means "Day of Atonement," and that pretty much explains what the holiday is. It is a day set aside to "afflict the soul," to atone for the sins of the past year. Yom Kippur is a 25-hour fast day that begins before sunset on the evening before Yom Kippur and ends after nightfall on the day of Yom Kippur when the shofar blasts one more time. One is supposed to refrain from eating and drinking (even water) on Yom Kippur. Most of the holiday is spent in the synagogue, in prayer. It is customary to wear white on the holiday, which symbolizes purity and calls to mind the promise that our sins shall be made as white as snow (Is. 1:18). Some people wear a kittel, the white robe in which the dead are buried to remind us that we are like dust of the earth without G-d.