Rambam - Sefer HaMitzvos: Positive Mitzvot 57, 56, 58: Positive Mitzvot 57, 56, 58

Positive Mitzvah 57: Slaughtering the Second Passover Offering
Numbers 9:11 "On the fourteenth day of the second month, at evening, they shall do it"

"It's never too late!"

The Torah declares that a Jew always has a second chance.

If someone was unable to bring the Paschal sacrifice because of impurity (see Positive Mitzvah 74) or because he was too far away to get to the Beit HaMikdash, he is given another opportunity.

This person is commanded to fulfill this obligation, a month later, on the fourteenth day of the month of Iyar.

Positive Mitzvah 56: Eating the Passover Offering
Exodus 12:8 "And they shall eat the meat on that night"

We are commanded to eat the Paschal sacrifice on the night of the fifteenth day of Nisan.

It must be roasted and eaten together with Matzot and bitter herbs.

Positive Mitzvah 58: Eating the second Passover Offering
Numbers 9:11 "And eat it with unleavened bread and bitter herbs"

The second Paschal sacrifice (see above, Positive Mitzvah 57) must be eaten on the night of the fifteenth day of the month of Iyar.

Just like the first, it is to be eaten with matzot and bitter herbs.

Doing good is not about being nice.
You can do nice things all day long for many people, but it could be all just more service of you own self, food for your own ego. He made a world where people would need each other, not so you could be nice, but to give you the opportunity to escape the confines of you own self. This is why the Torah says, "If you see the donkey of your enemy crouching under its load, and your response is to abandon him there -- then you must surely help him."
When you help those who show gratitude, when you lend a hand to those who are on your side, you are still within the realm of your own ego and self. Help someone you don't want to help. Help him and learn to want to help him -- only because this is the right thing to do. At first, it many not feel so rewarding. But you have sprung free.

From: Bringing Heaven Down to Earth by Tzvi Freeman - tzvif@aol.com