Shovavim
Shovavim is a period of six to eight weeks each year, in which some Kabbalists teach one should focus on repenting for one's sins, particularly sexual sins.
The term shovavim is a Hebrew acronym consisting of the initial letters of the parshioth of "Shemot", "Va'era", "Bo", "Beshalach", "Yitro" and "Mishpatim". The period in which these portions are read typically falls around Tevet-Shevat in the Hebrew calendar. During a Hebrew calendrical leap year, this period is extended to an eight-week sequence called "Shovavim Tat", derived by adding the next two portions, "Terumah" and "Tetzaveh", to the list.
When read as a Hebrew word, shovavim means "mischief-makers." This word appears in Jeremiah 3:22, which begins: "Return, mischief makers". The name shovavim is thus symbolic of the repentance which one is exhorted to do in this period.
History
There are several early sources for the fasting eight times in a leap year; the observance in a non-leap year is much later. The earliest source for Shovevim appears in Leket Yosher, where Joseph ben Isaac says that his teacher, Israel Isserlein would fast on the Thursday of these weeks in a leap year. The custom of fasting in a leap year is also mentioned in Sefer Haminhagim of Isaac Tyrnau.The early Kabbalists' practices took on a new meaning. First, they were expanded to include every year rather than only in a leap year. In this season, Kabbalists teach that repenting for sins is auspicious, especially sexually related transgressions.
During these weeks, it is customary to be more careful not to violate any of the sexually related transgressions commanded in the Torah. Some have the customs of studying laws relating to such transgressions, ta'anit, and giving extra tzedakah during this time, and of reciting Selichot and other tikkunim designed to counteract their harmful effects. On the Shabbats, when these weekly portions of the Torah are read, some take upon themselves to refrain from speaking, except words of prayer and Torah. This type of fast is called a ta'anit dibbur.
Since Kabbalistic teachings popularized these customs, Sephardic and Hasidic Jews are more likely to follow them than their Ashkenazi counterparts. Nevertheless, specific very traditional Eastern Ashkenazic communities, such as Golders Green Beth Hamedrash and Viyen follow the original custom to recite Selichot for these days in a leap-year only, individuals in these communities may fast as well.