PURIM KATAN (Heb. פּוּרִים קָטָן; "minor Purim"), the name given to the 14th and 15th days of the first month of *Adar in a leap year, when *Purim is celebrated during the second month of Adar. (The Karaites were the only sect to celebrate Purim during the first Adar in a leap year.) According to talmudic tradition, Purim should be celebrated in the second Adar because that was the date of the original Purim (which occurred in a leap year). The rabbis also wanted to bring the period of the redemption of Esther closer to that of the redemption of the Israelites from Egypt celebrated in the following month of Nisan (Meg. 6b). Purim Katan has none of the ritual or liturgical features of Purim: The megillah is not read, and no gifts are sent to the poor (Meg. 1:4). The *Al ha-Nissim prayer is not said, but fasting and funeral eulogies are prohibited (Meg. 6b). Also, *Taḥanun is not recited on these days, which are considered a minor occasion of rejoicing (Sh. Ar., oḤ 697:1).
Eisenstein, Dinim, 337; G. Ki-Tov, Sefer ha-Toda'ah, 1 pt. 1 (1958), 297.