Every year we are given the last time we are allowed to eat the Afikomen. Just as the קרבן פסח was to be consumed by midnight, so, too, should we finish our “dessert”, namely, the Afikomen by midnight.
Anyone who learned the first Mishna in Brachot knows that whenever there is a Mitzva to be completed by חצות, midnight, really has until עמוד השחר, daybreak, to complete the Mitzva. The Rabbis said חצות, in order to distance a person from sinning.
Even though, technically, the same applies after the fact, by אפיקומן, there is a difference. If one only started his Seder after midnight for whatever reason, he can only say the Bracha of המוציא on the Matza, and is no longer allowed to say the once a year Bracha of על אכילת מצה.
It’s good to have a perspective on things. But it’s even better to do things on time.