By Rav Avraham Chaim Bloomenstiel
Question: If I keep the zman Rabbeinu Tam for motzei shabbos and holidays, must I observe it for fast days as well?
Answer: There are three shittos in the poskim.
- Yalkut Yosef 293:4 and Shearim Metzuyanim Bihalacha 123:4 pasken that those who hold of Rabbeinu Tam’s zman may end rabbinic fasts earlier, relying upon the zeman of the Gra.
- The Divrei Yatziv 230 writes that one should hold of R’Tam even by d’rabbanon fasts. However, if it is difficult, one may break his fast after only 60 minutes.Â
- The Yisroel ve-HaZemanim, v. I, p. 573-578 writes that one who holds of Rabbeinu Tam must do so by the rabbinic fasts as well.
The common minhag is like the Yalkut Yosef and the Shearim Metzuyanim – one need not hold of Rabbeinu Tam’s zeman to end rabbinic fasts even if he usually relies upon Rabbeinu Tam for ending shabbos.
