Pesach Sheni

Pesach Sheni
Many eat matzo on Pesach Sheni in remembrance of the Korban Pesach
Official name	Hebrew: פסח שני‎‎
Also called	Translation: "Second Passover"
Observed by	Jews
Type	Jewish
Significance	Day to make up the Korban Pesach (Pascal lamb sacrifice) if missed on Passover
Celebrations	Some Chasidic Jews conduct a seder resembling a Passover seder
Date	14th day of Iyar
2016 date	May 22
Related to	Passover

Pesach Sheni (Hebrew: פסח שני, trans. Second Passover) occurs every year on 14 Iyar. This is exactly one month after 14 Nisan, the day before Passover, which was the day prescribed for bringing the Korban Pesach ("Paschal offering", i.e. Passover lamb) in anticipation of that holiday. As described in the source text for this mitzvah (Numbers 9:1-14), the Israelites were about to celebrate Passover one year after leaving Egypt.

The offering of the Korban Pesach was at the core of that celebration. However "certain men" were ritually impure from contact with human corpses, and were therefore ineligible to participate in the Korban Pesach. Faced with the conflict of the requirement to participate in the Korban Pesach and their ineligibility due to impurity, they approached Moses and Aaron for instructions, which resulted in the communication of the law of Pesach Sheni.

As described in Numbers 9:9-13, a Jew may bring the Korban Pesach on Pesach Sheni if s/he is ritually impure due to contact with a dead body or were on a "distant journey". As elucidated in Mishnah Pesahim (9:1-4) and its Gemara:

In net effect, anyone unavoidably prevented from offering the Korban Pesach on Passover may do so on Pesach Sheni. However one may not intentionally defer the Korban Pesach if it is in his/her power to offer it on Passover.

The Mishnah (9:3) and Gemara outline the following similarities and differences in the laws of the Korban Pesach when it is offered on Pesach Sheni, compared to when it is offered on Passover:

Due to the destruction of the Temple in Jerusalem, Jews are unable to perform the Passover sacrifice, neither on Passover nor on Pesach Sheni. Some have the custom to eat matzo during Pesach Sheni in memory of the sacrifice. Some have the custom to omit Tahanun from the daily prayer service, though this custom is not observed universally.