 The evening Shema should be recited by now, and the Afikoman on Passover should be eaten by this time.The Talmud in Berachot rules that all "night" mitzvot should be performed by "Chatzot," at least "ab initio," in case the person would otherwise fall asleep and then fail to perform the mitzvot.Some rise at this time and recite "Tikkun Chatzot", a series of supplications for the rebuilding of the Temple.