Yom Kippur is the holiest day of the Jewish religious calendar. It is the "Day of Atonement" when Jews individually, and as a religious community, confess their sins and ask for God's forgiveness. It was instituted when the Israelites still wandered in the desert. The Scripture reference is found in Exodus 30:10; Leviticus 23:27-31, 25:9; and Numbers 29:7-11.
Yom Kippur is observed with solemn ritual in the synagogues and in the home, with fasting and prayer. The most observant Jews will refrain from eating, bathing, wearing leather shoes, anointing themselves with oil, and marital relations for 25 hours: from one hour before sunset to sunset the next day. Although fasting is required, it is waived for those for whom it might be harmful, such as diabetics.
A large feast is held the afternoon before Yom Kippur officially begins. This feast may be a dairy feast, or one including meat, since Kosher dietary laws prohibit eating dairy products and meat at the same meal. Kugel, a noodle dish, sweet potatoes and pumpkin recipes, as well as honey cake or baked chicken are all popular foods for the pre-fast Yom Kippur meal, for Ashkenazi Jews. Some Sephardic Jews may eat similar foods, but their cuisine also reflects their geographical roots, and may include couscous, olives and other Mediterranean influences.
In the synagogue, Yom Kippur is observed with an evening service where the men wear their tallits, or prayer shawls. This is the only service of the year when this is done. A morning service is held the next day and the blowing of the shofar, or ram's horn bugle, ends the observance.
Yom Kippur falls on the tenth day of Tishrei in the Hebrew calendar. This translates to September or October in the common calendar. Many Jews who are not otherwise observant come to services on this day. It's rather like Easter or Christmas for that in the Christian tradition.
Numerous Yom Kippur recipes and resources are available online for those looking for ideas or inspiration for a special observance of the holiest of high holidays in the Jewish tradition.