New Day's Day is an annual Fraggle holiday, as seen in the Fraggle Rock: Back to the Rock episode "Flight of the Flutterflies." The holiday celebrates the birth of new Flutterflies and is treated by the Fraggle populace as a way of celebrating new life and new beginnings.
The festivities involve the Troubadours, who bring a special box containing Flutterfly cocoons. A lucky Fraggle is then given the role of giving a holiday speech and opening the box to release the newly-hatched Flutterflies. The particular Fraggle earns the role through a game of Skitter-Skatter, in which they must be the one to catch the Skitter Stone (unless it chooses someone in particular). Only the chosen Fraggle can open the box of Flutterflies, otherwise it will explode from the interior commotion of hatching bugs.
Boober ends up being the unwitting Fraggle to perform the ritual, but he finds the holiday pointless. He eventually comes to learn that to properly celebrate the day, he can't let his constant fear take over.