Hilchos Pesach – 1

1. We begin learning the halachosof Pesach thirty days before Pesach. However, there is an additional obligation to study the laws of the festival during the festival itself (Shulchan Aruch and Mishnah Berurah 429).

2. Some say that the obligation to begin studying the laws of the festival thirty days in advance applies to all festivals, while other opinions maintain that it only applies to Pesach because of its numerous laws. For other festivals, however, it is sufficient to begin learning their laws just a few day before the festival (ibid.).