1. A person who did not search for chametzin his home on the night of the fourteenth of Nissan, should search during the day, as soon as he remembers. If he did not search during the day of the fourteenth, he should search during the festival of Pesach. If he did not search during Pesach, he should search after Pesach, so that he will not stumble on the prohibition of chametz that was owned by Jews] during the Pesach — whose benefit is forbidden (Shulchan Aruch and Mishnah Berurah 435).
2. If the person is doing the search on the eve of Pesach [i.e., during the day of the fourteenth,] or during the week of Pesach, he recites the blessing for the search. But if he is searching after Pesach, he does so without the blessing. Every search, even if done by day, must be done with the light of a candle [or flashlight], and the search must include the holes and crevices (ibid.).

