Yom Kippur Katan - AbsoluteAstronomy.com

Yom Kippur Katan is a practice observed by some Jews on the day preceding each Rosh Chodesh

Rosh Chodesh

Rosh Chodesh or Rosh ḥodesh is the name for the first day of every month in the Hebrew calendar, marked by the appearance of the new moon. The new moon is marked by the day and hour that the new crescent is observed...

or New-Moon Day, the observance consisting of fasting and supplication, but being much less rigorous than that of Yom Kippur

Yom Kippur

Yom Kippur , also known as Day of Atonement, is the holiest and most solemn 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...

proper.

The custom is of comparatively recent origin and is not mentioned in the Shulchan Aruch

Shulchan Aruch

The Shulchan Aruch also known as the Code of Jewish Law, is the most authoritative legal code of Judaism. It was authored in Safed, Israel, by Yosef Karo in 1563 and published in Venice two years later...

. It appears to have been inaugurated in the sixteenth century at Safed

Safed

Safed , is a city in the Northern District of Israel. Located at an elevation of , Safed is the highest city in the Galilee and of Israel. Due to its high elevation, Safed experiences warm summers and cold, often snowy, winters...

by the kabbalist Moses Cordovero

Moses ben Jacob Cordovero

Moses ben Jacob Cordovero, , was a central figure in the historical development of Kabbalah, leader of a mystical school in 16th-century Safed, Israel. He is known by the acronym the Ramak....

(Da Silva, "Peri Ḥadash," Rosh Ḥodesh, § 417), who called the fast Yom Kippur Ḳaṭan; and it was included by Isaac Luria

Isaac Luria

Isaac Luria , also called Yitzhak Ben Shlomo Ashkenazi acronym "The Ari" "Ari-Hakadosh", or "Arizal", meaning "The Lion", was a foremost rabbi and Jewish mystic in the community of Safed in the Galilee region of Ottoman Palestine...

in his Seder ha-Tefillah. R. Isaiah Horowitz

Isaiah Horowitz

Isaiah Horowitz, , also known as the Shelah ha-Kadosh after the title of his best-known work, was a prominent Levite rabbi and mystic.-Biography:...

refers to it by that name, and says it should be observed by fasting and repentance: "Following the custom of the very pious, one must repent of his ways and make restitutions both in money and in personal acts, in order that he may enter the new month as pure as a new-born infant" (Shelah, ed. Amsterdam, 1698, pp. 120b, 140a, 179a). When Rosh Ḥodesh occurs on a Sabbath or Sunday, Yom Kippur Ḳaṭan is observed on the preceding Thursday. The fasting is not obligatory, and only the very pious observe that act of self-denial.

The liturgy of the day, which consists of selichot

Selichot

Selichot or slichot are Jewish penitential poems and prayers, especially those said in the period leading up to the High Holidays, and on Fast Days...

, is recited at the Mincha

Mincha

Mincha, מנחה is the afternoon prayer service in Judaism.-Etymology:The name "Mincha" is derived from the meal offering that accompanied each sacrifice.-Origin:...

prayer in the afternoon. Tallit

Tallit

A tallit pl. tallitot is a Jewish prayer shawl. The tallit is worn over the outer clothes during the morning prayers on weekdays, Shabbat and holidays...

and tefillin

Tefillin

Tefillin also called phylacteries are a set of small black leather boxes containing scrolls of parchment inscribed with verses from the Torah, which are worn by observant Jews during weekday morning prayers. Although "tefillin" is technically the plural form , it is loosely used as a singular as...

are adjusted, and if there are among the congregation ten persons who have fasted, they read from the scroll Va-Yechal ( et seq.). The selichot are taken partly from the collection used on the general fast-days and Yom Kippur, with the Viddui ha-Gadol (the great confession of sin by Rabbenu Nissim

Nissim Ben Jacob

Nissim ben Jacob , was a rabbi best known today for his Talmudic commentary ha-Mafteach, by which title he is also known.-Biography:Rav Nissim studied at the Kairouan yeshiva, initially under his father - Jacob ben Nissim who...

) and Ashamnu, and also a beautiful poem written for the occasion by Leon of Modena

Leon of Modena

Leon Modena or Yehudah Aryeh Mi-modena was a Jewish scholar born in Venice of a notable French family that had migrated to Italy after an expulsion of Jews from France.-Life:...

and beginning with Yom zeh. Some congregations add Avinu Malkenu. The fast ends with the Mincha prayer. For the text see Baer, 'Abodat Yisrael, pp. 317-319; Emden's Siddur Bet Ya'aḳob, ed. Warsaw, pp. 212a-216b.

Further reading