In rabbinic law, "tzitzit" is considered a "time-dependent positive commandment", as the Torah (Numbers 15:39) mentions "seeing" one's tzitzit, and one could not see them in the darkness of night, but rather only in daytime. In general, women are not required to perform time-dependent positive commandments, but may perform them if they choose to. Therefore, many Rishonim permitted women to wear "tzitzit" (including Isaac ibn Ghiyyat, Rashi, Rabbeinu Tam, Baal HaMaor, Rambam, Raaviyah, Rashba, and Ra'ah). Similarly, the Shulchan Aruch rules that women may wear garments with "tzitzit". Opinions differ on whether women may make the blessing on such "optional" commandments; in general Ashkenazi women make the blessing, and Sephardic women do not.