The day before Rosh Chodesh, the first of each Hebrew month, is identified, in Jewish kabbalistic tradition, as Yom Kippur Katan, meaning Little Yom Kippur. As the name implies, this is a day of fasting for atonement, allowing the participant to enter the new month with a clean slate. The inspiration for Yom Kippur Katan comes from the biblical prescription to bring a sin offering on the first of every month (Numbers 28:15).
The practice is not mentioned in the Talmud or the Shulchan Aruch, Judaism’s foremost law code, but seems to have originated later with the kabbalists of Safed, with Rabbi Moses Cordovero (16th century) sometimes identified as the originator. According to some sources, it was never a fast observed by the entire community, but the reserve of particularly pious members. However, a disciple of Cordovero wrote that it was observed by men, women and even schoolchildren. He states that they spent the day in prayer and confession and even self-flagellation.
Yom Kippur Katan is not observed four months of the year because it is set aside in deference to major Jewish holidays. The days before Rosh Chodesh Tishrei and Rosh Chodesh Heshvan are skipped because of their proximity to Rosh Hashanah and Yom Kippur. The days before Rosh Chodesh Tevet and Rosh Chodesh Nisan are also not fast days because the first falls during Hanukkah and the second is part of the Passover season. If the last day of a month falls on a Shabbat, Yom Kippur Katan is moved back to Thursday.
Never a universal Jewish practice, in contemporary times Yom Kippur Katan is largely not observed, though there has been a resurgence of interest in recent years.
Pronounced: kah-bah-LAH, sometimes kuh-BAHL-uh, Origin: Hebrew, Jewish mysticism.
Pronounced: TALL-mud, Origin: Hebrew, the set of teachings and commentaries on the Torah that form the basis for Jewish law. Comprised of the Mishnah and the Gemara, it contains the opinions of thousands of rabbis from different periods in Jewish history.
Pronounced: yohm KIPP-er, also yohm kee-PORE, Origin: Hebrew, The Day of Atonement, the holiest day on the Jewish calendar and, with Rosh Hashanah, one of the High Holidays.