Pesach Sheni: It’s never too late!
Pesach Sheni ("the Second Pesach") is celebrated on Iyar 14 – one month after Pesach.
The Torah relates that in the year following the Exodus from Egypt, the Jews made preparations to bring the Pesach sacrifice. However, a few men were disqualified on the grounds of ritual impurity, as a result of having performed burials. Disturbed at their inability to partake in the offering, they came before Moshe and cried, "Lamah nigara – why should we lose out on bringing the offering of G-d in its correct time?!" In reply, Hashem instructed the Jews in the laws of Pesach Sheni – "If any man be ritually-impure ... or on some distant journey" on Nisan 14, the day of the Pesach sacrifice, then he may instead bring the offering in the next month, on Iyar 14.
The ability to correct what had seemed to be a lost opportunity extended even to one who deliberately transgressed G-d's command to bring the sacrifice on Pesach. Even he received a second chance on Pesach Sheni.
The eternal message of this day, writes the Rebbe (Hayom Yom, Iyar 14), is that it is never too late; it is always possible to put things right – even if one is [spiritually] "impure" or "distant," and even when this failing was deliberate, nevertheless, he or she can correct it.
[I.e., a month after the Pesach sacrifice, which is offered on Nisan 14 and eaten that night (Nissan 15) during the Pesach Seder.]
Bamidbar 9:6-11; see Sukah 25a.