What is Pesach Sheni? Pesach Sheni, observed on the 14th of Iyar, exactly one month after the eve of Pesach, is a deeply meaningful and often overlooked day on the Jewish calendar. In the days of the Bet HaMikdash, this day provided a unique opportunity for a "makeup" Korban Pesach for those who, due to circumstances beyond their control such as ritual impurity or being on a distant journey and were unable to offer the Korban Pesach on its proper time, the 14th of Nissan.