|Pesach Katan, Second Pesach, Little Pesach|
|A semi Jewish holiday presenting a 2nd opportunity to bring the Pesach sacrifice.|
Pesach Sheni is a semi Jewish holiday that was observed mostly until the destruction of the 2nd Temple. Falling out on the 14th of Iyar, it presented a second opportunity for people that had been impure or distant from Yershalaim on Peasach to bring the Korban Peasch. It was on this day that the Matzos brought out of Egypt by the Jewish Nation ran out and the mon started falling the following morning. Hillulas of Rebbe Meir Baal Haness and Rabbi Yehuda bar Ilai are celebrated on Pesach Shani. In current times there are very minor Halachic differences for Pesach Shani, aside from a number of Minhagim of which the most common is eating leftover Matza from Pesach.
 14th of Iyar
 Egyptian Matzos Finished
Due to the great rush to leave Egypt the bread baked by the Jews for their journey did not have time to rise and remained in the form of Matzos. These Matzos lasted the Jewish Nation for an entire month and ran out only on the 14th of Iyar. On the following morning of the 15th of Iyyar the Mon started falling.
 Iyar a Replacement for Nisan
Before Hillel Nessia established the set Jewish calendar, leap years were established on a year to year basis. Since each year had the potential of becoming a leap year, every month of Nisan had the possibility of turning into Adar Bais, thereby making Iyar into Nisan. This in essence means that Iyar has an overlapping spiritual essence with Nisan, therefore a secondary version of Pesach could be inserted in this month.
 Residue of Pesach Energy
According to the Kabbalah the spiritual energy brought down during the holiday of Pesach remains to a certain degree, for thirty days. Since Yud Dalled Iyyar is the last of these days, Pesach Shani was established on this day, thereby allotting the most possible time for people to purify themselves and reach Yerushalaim before the energy of Pesach is completely gone. Now that Pesach Sheni was established it extends this spiritual energy for another seven days, as Pesach Sheni reflects the light of the full seven days of Pesach. After this, the gates are completely closed for these Tikkunim.
 Kurban Pesach
Falling out exactly a month after the first night of Peasch (14th of Nisson), the sacrifice of Pesach Shani would be brought in the late afternoon of the 14th of Iyyar and was eaten on the night of the 15th of Iyyar. There are a number of differences between a the initial Kurban Pesach and the Pesach Sheni version.
 Chamatz With Matza
Unlike Pesach where leaven is forbidden, it is permissible to eat Chametz along with Kurban Pesach and matzos on Pesach Sheni, just like in the initial Pesach Sheni when the Matzos taken out of Egypt ran out.
 Pesach Katan
Pesach Sheni is also called 'Pesach Katan' or the 'Little Pesach' for a few reasons...
- Pesach Sheni lasts for only one day in contrast with Pesach that lasts seven days.
- Pesach Sheni has many halachic leniencies that do not apply on Pesach.
- Only a minority of the nation celebrated Pesach Shani since the majority already brought their Kurbon on Pesach.
 Pesach Sheni Today
Although Pesach Sheni was created for the era of the Beit Hamikdash, there are still Halachic ramifications today as well as a number of Minhagim. Unlike other extinct Jewish holidays such as those inscribed in Migilas Tanis, Pesach Sheni will once again be revived at the time of the Redemption, therefore its celebration is continued to a certain degree.
Most communities do not say Tachnun on Pesach Shani. It is customary not to eulogize the dead on this day and it is prohibited to fast.
There is a widespread minhag to leave over some Matza from Pesach, preferably Shemura Matza and then eat it on Pesach Sheni. There is also a custom to be joyous on this day since it is holy.
In some Chasidik groups the Rebbe holds a Tish for his Chasidim on Pesach Sheni. This is especially prevalent in Nadvorna where they conduct a tish with four cups of wine, matza and maror, similar to the seder. In Na Nach they recite the Petek and joyously chant Na Nach Nachma Nachman Meuman. This is especially true for the Nanachs who attend the Hillulah of Rebbe Meir, the location where the Petek came down from Heaven.
Each year on Peasach Shani the hillula of Rebbe Meir Baal Haness is celebrated in Teveria and the hillula of Rabbi Yehuda bar Ilai is celebrated in Ein Zettim. Although there is no early sources that stating Yud Daled Iyar as the date of their Yartzheits, this is what became established over the years. This can possibly be due to its proximity to Lag Baomer when thousands of visitors would head up to the Galill for the Hillula of Rebbe Shimon bar Yochi.