How many hours does the Yom Kippur fast typically last?

The Yom Kippur fast typically lasts 25 hours. It begins before sunset on the eve of Yom Kippur and continues through the next day until after nightfall.

The fast is longer than a neatly measured 24-hour period because Jewish observance adds time at both ends of the holiday. The start is brought forward before sunset, and the end is delayed until nightfall, allowing a customary margin around the transition between days. Jewish days themselves begin and end at sunset rather than midnight.

During the traditional fast, observers abstain from food and drink, including water. Yom Kippur also involves prayer, confession, repentance and other forms of self-denial. People whose health could be endangered are not expected to follow the fast in a way that risks life; Jewish legal and medical guidance gives preserving life priority.

A common mistake is to call it simply a 24-hour fast or to compare it with Ramadan’s daily fasts. Ramadan fasting recurs each day over a month, whereas Yom Kippur is one annual, continuous fast. The actual clock duration varies slightly by location and local sunset and nightfall times.