Observed in Countries with Jewish populations, especially Israel, United States, and Canada
Observed on Tenth of Tishri, the seventh month of the Jewish calendar
Observed by Jews

Yom Kippur is one of the most important holidays of the year for Ashkenazi and Sephardic Jews. Even those Jews who do not adhere to most traditions and customs make it a point to refrain from work, attend synagogue, and fast on this day. It is one of the Days of Awe (Yamim Noraim), which includes Rosh Hashanah, the first two days of the ten days of repentance, and Yom Kippur, the last of the ten days. It falls on the tenth day of Tishri, the seventh month of the Hebrew calendar (September–October).
It closes the 10-day period of penitence that Rosh Hashanah (the New Year) began. Yom Kippur is a total Sabbath (day of rest), when work of any kind is prohibited, and the devout abstain from eating; they do not even drink water on this day.
According to research, about 75 percent of the Jews in Israel fast on Yom Kippur, including those who do not think of themselves as being religious.
Yom Kippur means “day of atonement,” a day set aside at the end of Rosh Hashanah to repent for one’s sins of the past year. This day is basically the last chance to show regret and make amends so as to ameliorate God’s judgment relating to those sins.
On Yom Kippur one atones only for the sins between oneself and the Creator, not for sins committed against another human being. To seek forgiveness for the sins against another person, a compromise with that person must be arrived at, and if possible the trespass, forgiven. This return to harmony must be accomplished before Yom Kippur begins, because this is the day when God closes the books, and one’s fate, for better or worse, is sealed.
Even the deceased are included in the category of those forgiven on the Day of Atonement. Children must make a public mention of their deceased parents at the synagogue and donate to various charities on behalf of their departed souls.
Before sunset on Yom Kippur, the Kol Nidre is recited. This prayer is well known for its beautiful melody; Kol Nidre (meaning “All Vows”) annuls all vows that the individual may make to God in the year to come before they are uttered; the annulment voids only those vows made between oneself and God, especially the frivolous vows one makes to God when seeking help or religious vows made under duress (for example, coerced conversion to another religion). The recitation of the Kol Nidre does not change the fact that obligations toward other people must be upheld. In fact the eve of Yom Kippur is considered one of the best times to seek and grant forgiveness. God will forgive sins committed against him; but if one has wronged another person, then he or she must seek forgiveness from that person and try to make amends.
The viddui, or confession, is recited as part of the afternoon prayers the day before the holiday begins.
Even though viddui is repeated throughout Yom Kippur, it is repeated because, were someone to die later in the day, he or she would at least have already chanted the confessional and sought forgiveness.
Most of Yom Kippur is spent praying in synagogue.
Services begin early in the morning in Orthodox synagogues and continue until the afternoon.
People then go home, returning soon afterward for the evening service that continues until nightfall. The services conclude with the blowing of tekiah gedolah, an extended blast on the shofar (a Jewish musical instrument originally carved out of a ram’s horn).
There are numerous traditions concerning how the fast of Yom Kippur is to be broken. Some break it with a potato, some with an egg (symbolizing the renewal of life in the new year). While there is no correct menu to serve, it is certainly desirable to invite friends, relatives, and family members to share it. Traditionally people are supposed to eat only enough to revive their strength and then proceed to the next mitzvah (holy action or festival).

Origins and History
Yom Kippur was first set forth In the Bible, chapter 16 of Leviticus, where the rituals are described. Yom Kippur is called Shabbat Shabbaton (Sabbath of Sabbaths), because it is on Yom Kippur that abstention from work and the solemnity that characterize the Sabbath are most important. The fast of Yom Kippur is strict: Taking a bath, using cosmetics, perfumes, or deodorant, engaging in sexual intercourse, wearing leather (including shoes), eating or drinking, and working are forbidden. Yom Kippur is a full, 25-hour fast starting before sunset on the evening preceding the festival day, and culminating after nightfall on Yom Kippur. These restrictions may be waived in case of any ailment, health hazard, or terminal disease. Children under nine years of age and pregnant women are exempted from fasting. Older children, as well as new mothers (defined as those who have given birth between three and seven days following previous), are expected to fast but are permitted to break the fast if they need to do so.
During the days of the Second Temple in Jerusalem (516 B.C.E.–70 C.E.), the high priest conducted an elaborate sacrificial ceremony on Yom Kippur. Clad in white linen, he successively confessed his own sins, the sins of the other priests, and lastly the sins of the people; then he entered the Sanctum Sanctorum (Holy of Holies) to sprinkle the blood of the sacrifice and offer incense. The priest would then send a goat (the scapegoat) into the wilderness, where it was driven to its death, symbolically carrying away the sins of the people of Israel. Some commentators believe that the killing of the goat was a misinterpretation and that the goat was set free.
The old custom of kapparot, or atonement, was formerly practiced on the afternoon before the holiday.
The custom involved swinging a live chicken around one’s head and saying a specific prayer. Later the chicken was killed, and its meat given to the poor. Nowadays, money is tied up in a handkerchief and used instead of the chicken. It is eventually donated to charity.