It is customary to remain awake throughout the night of Shabuot and immerse oneself in Torah learning. The Shela (Rabbi Yeshaya Horowitz, 1565-1630) records a famous incident that occurred during the times of Maran (Rabbi Yosef Karo, author of the Shulhan Aruch, 1488-1575) that underscores the importance and inestimable value of this custom. He and several colleagues remained awake throughout the night of Shabuot studying Torah, and in the middle of the night, a heavenly voice announced to them that their learning was bringing indescribable delight and enjoyment to the heavens. However, the voice added, if they had a Minyan studying together, then they would bring even greater joy to the heavens, and their learning would attain an even higher level. Maran related this incident to the people the next day, and on the second night, they assembled a Minyan and again remained awake throughout the night. And that night, too, a voice burst forth from the heavens emphasizing the immense joy they brought to the Almighty.
This incident demonstrates the unique importance and significance of this practice, and the profound impact it has upon the upper worlds.
The custom is to read the special "Tikkun" which appears in Keri’eh Mo’ed. One should not belittle the importance of this reading. Even though it consists of simple verses and passages, this is a time-honored custom that should be respected and followed. The "Tikkun" generally takes approximately 2-3 hours (depending, of course, on the speed at which it is read), and after one completes the reading, he is certainly allowed and encouraged to study Gemara or any other area of Torah that he wishes to learn.
Everyone should make a point of observing this ancient custom, and it is advisable to rest on Ereb Shabuot so that one will be able to remain awake throughout the night.
It must be noted, however, that this custom which has been observed for generations certainly did not entail remaining awake throughout the night and then sleeping the entire next day. This accomplishes nothing other than reversing night and day, which has no value whatsoever. Undoubtedly, the custom was – and should be – to remain awake throughout the night, sleep a few hours after Shaharit to regain one’s strength, and then learn Torah during the day. This is, without question, the way the custom was practiced, and this should be our practice, as well, each year on Shabuot.
Summary: One should make every effort to observe the time-honored tradition to remain awake studying Torah on the first night of Shabuot, and to rest before the onset of Yom Tob to help him remain awake during the night. One should read the traditional "Tikkun" and then spend the remaining hours studying whichever area of Torah he chooses. One should not sleep the entire next day; he should instead sleep for several hours to regain his strength and then continue studying Torah.
