Yom Kippurיוֹם כִּפּוּר

Yom Kippur (Hebrew: יוֹם כִּפּוּר or יום הכיפורים), also known as the Day of Atonement, is the holiest day of the year for the Jews. Its central themes are atonement and repentance. Jews traditionally observe this holy day with a 25-hour period of fasting and intensive prayer, often spending most of the day in synagogue services. Yom Kippur completes the annual period known in Judaism as the High Holy Days (or sometimes “the Days of Awe”). Yom Kippur is the climax of the Ten Days of Repentance (the Days of Awe) that open on Rosh Hashanah. Its themes are atonement (kapparah) and repentance (teshuvah): tradition holds that the divine judgment opened on Rosh Hashanah is sealed on this day, so the liturgy is built around confession (vidui) and a plea for forgiveness. A crucial principle distinguishes the day's reach: Yom Kippur atones for transgressions between a person and God, but for wrongs done to other people one must first seek reconciliation and forgiveness directly from the person harmed. In Temple times it was the single day each year on which the High Priest (Kohen Gadol) entered the Holy of Holies to offer incense and effect atonement for all Israel, a service the modern liturgy recalls in the Avodah.

Yom Kippur falls on 10 Tishrei, the tenth day of the Hebrew month of Tishrei. Unlike most festivals, it is observed as a single day in both Israel and the Diaspora. It is not doubled outside Israel because of the severity of adding a second fast day. The observance begins at sundown on the evening of 9 Tishrei (Erev Yom Kippur / Kol Nidre night) and ends at nightfall the following day, spanning an approximately 25-hour fast. On the Gregorian calendar it falls in late September or early October.

The morning (Shacharit) Torah reading is Leviticus 16:1-34, the High Priest's Yom Kippur Temple service and the ritual of the two goats, read in 6 aliyot (7 when Yom Kippur falls on Shabbat). The Maftir, from a second scroll, is Numbers 29:7-11 (the day's offerings), and the morning Haftarah is Isaiah 57:14-58:14, on the sincere fast that God desires. In the afternoon (Mincha), the Torah reading is Leviticus 18:1-30 on forbidden relationships (read in 3 aliyot; some communities or rites read Leviticus 19 instead), and the Haftarah is the entire Book of Jonah (1:1-4:11), concluding with Micah 7:18-20 on repentance and divine mercy. The Torah is chanted in the special High Holiday Torah trope (a distinct, solemn melody shared with Rosh Hashanah morning), while the Haftarot are chanted in the standard Haftarah trope.

The day is marked by five traditional prohibitions ("afflicting the soul"): no eating or drinking (the full ~25-hour fast), no washing or bathing, no anointing with oils or cosmetics, no wearing leather shoes, and no marital relations. Many wear white, often a kittel (the same white robe worn at weddings and burials), to symbolize purity, drawing on Isaiah 1:18 ("though your sins be as scarlet, they shall be white as snow"). Five prayer services structure the day: Maariv with Kol Nidre (the one weekday evening a tallit is worn), Shacharit, Musaf (which includes the Avodah re-enacting the High Priest's Temple service, and the Martyrology), Mincha, and the unique closing service Neilah ("the locking of the gates"), recited with the ark open and the congregation standing. The communal confession (Vidui, including Ashamnu and Al Chet) is recited repeatedly in the plural with a symbolic striking of the chest. Yizkor memorial prayers are recited (primarily in Ashkenazi practice). The fast ends with a single long blast of the shofar, followed by a break-fast meal.