There are a number of fast days spread throughout the Jewish calendar. The best known is Yom Kippur, the Jewish Day of Atonement, which is also the only fast day prescribed in the Torah (Five Books of Moses). However, there are also a number of other fast days in the Jewish calendar.

Fasting – what does this mean? and who fasts?

Fasting in Judaism involves not eating and not drinking. This is interpreted quite strictly – thus, for example, brushing teeth is not allowed on a fast day as this mean lead to the person inadvertently swallowing water.

Adults (anyone over the age of Bar or Bat Mitzvah) are expected to fast on fast days, but children under the age of 9 years do not fast as this is considered potentially harmful to their health and development. Between the ages of 9 years and Bar or Bat Mitzvah children are allowed to gradually fast for a greater part of the day each year so that they progressively become accustomed to fasting.

Just as young children are exempt from fasting on health grounds, so too are older people whose health may genuinely be adversely affected. Thus, for example, a person who takes medication to control a life-threatening condition is allowed to take their medication on Yom Kippur, and a person with diabetes who controls their diabetes through eating frequent small meals is allowed to eat on Yom Kippur (since fasting would likely result in them falling into a diabetic coma). Dispensations may also be available for those who become ill as a result of fasting (e.g. by developing migraines), but a rabbi should be consulted.

Fasting is regarded by the rabbis as a way of helping us focus on spiritual concerns rather than on physical concerns such as eating.

How long is a fast?

Judaism has two major fast days, Yom Kippur (the Day of Atonement) and Tisha b’Av (the 9th of Av, the anniversary of both the 1st and 2nd destruction of the Temple in Jerusalem). The description ‘major’ means that these fasts last for an entire day, approximately 25 hours from sunset on one day until nightfall on the following day.

Judaism also has a number of ‘minor’ fast days – in this context, ‘minor’ means that the fast lasts only from sun rise to nightfall. These minor fast days include the Fast of the First-Born (immediately before Passover), the Fast of Esther (before Purim), the Fast of Gedaliah (on the day after Rosh HaShanah), the 17th of Tammuz, and the 10th of Tevet (both commemorations of sad events in Jewish history).