The Jewish High Holidays end with Yom Kippur, widely considered the holiest day of the Jewish calendar.

Also known as the Day of Atonement, the holiday is an opportunity to seek repentance and reconciliation with God.

This year the holiday will be celebrated from sunset on October 11th until nightfall on October 12th. Many Jews mark the holiday with a 25-hour fast from food and drink and ask friends and family for forgiveness before the celebrations begin.

Five prayer services take place on Yom Kippur. The first occurs on the eve of the holiday, when the famous Kol Nidre prayer is often said. According to Encyclopedia Britannica, this prayer begins with an expression of repentance for all unfulfilled vows and promises made to God over the past year.

The last of the holiday’s five services takes place before sunset the following day. Services end with closing prayers and the blowing of a ceremonial horn known as a shofar, according to Judaism 101.

According to Chabad.org, before fasting begins, many Jews partake in a pre-sunset feast, often consisting of bland and unsalted foods to minimize thirst.

A Lenten meal after the final Yom Kippur service can include eggs, bagels and savory foods such as herring dishes and smoked salmon, according to Bon Appetit. According to the American Jewish Committee, even Jews who do not celebrate other holidays often take time off work and attend religious services to observe the holiday.

Traditions also vary between sects of Judaism: Orthodox Jews prohibit wearing leather shoes and anointing with oil during Yom Kippur and often wear white robes called smocks, according to Encyclopedia Britannica.

Adrian Ashford covers faith and religion in North Texas for The Dallas Morning News as part of a partnership with Report for America.