Q: I rented an apartment for the duration of Sukkos at a certain price. When it became clear to the landlord that I intended to remain through Simchas Torah, he asked for additional payment, claiming that Shemini Atzeres and Simchas Torah are not part of Sukkos. Must I add a sum?

A: Technically, Sukkos is seven days, whereas the eighth day (and ninth outside of Israel) is Shemini Atzeres. The Gemara (Rosh Hashanah 4b; Sukkos 48a) teaches that Shemini Atzeres is considered an independent festival in six respects.

However, in common parlance, Sukkos includes Shemini Atzeres. The Ran (Nedarim 49a, s.v. Yerushalmi) cites a dispute regarding one who disavows wine for the duration of Sukkos, whether we follow the Torah’s terminology that Shemini Azteres is independent, or the people’s common parlance. We rule that vows follow the people’s parlance, and Shemini Atzeres is included in the chag (Y.D. 220:20; Shach 220:34).

Monetary law also follows the people’s parlance, like vows (Rashba 4:161; C.M. 215:8). Thus, a contract for the duration of Sukkos includes Shemini Atzeres, unless specified otherwise.