A. The Jews originally received the Torah in May/June during the festival of Shavuot. Moses spent 3 sets of 40 days up on the mountain (the first time around, the 2nd set was to get the Jews forgiven for the Golden Calf, the third set was to get the 2nd set) and he finally came down with the 2nd Tablets on Yom-Kippur, which is the Jewish day for forgiveness and atonement. Right after Yom-Kippur is the Sukkot holiday, so the study of Torah anew each year begins right after that.