Hi ZeesKite: What do you mean by ‘before’? An hour? A day? A lunar cycle?
Seriously — IMHO, Learning is permitted at all times (except erev Tisha Be’Av and Tisha Be’Av and Aveilus R”L — some ‘restricted’ learning is permitted during the aforementioned).
But your question is actually a serious one, because I saw it brought down that there are those who refrain from napping/sleeping on Erev Sukkos (during the day/afternoon), since the ikar mitzvah of LeShev BaSukkah is to sleep in the Sukkah (compared to Matzah before the Seder).