The holiday season lasts all year long in Hell. It is forever. For this reason, seasonal music plays continually, without respite, except for the month of December when it is the hits of the 1910 Fruitgum Company over and over and over.
Though it has been repeatedly stressed it warrants one more iteration: time is non-existent in Hell so December is really a pointless concept, as is the holiday season. But the Devil likes the look of ongoing distress the music produces in the Damned so he keeps his iPod playing through the sound system — the Christmas playlist, on shuffle. Forever.
Santa is in Hell too, stuck in a fireplace where a fire rages till the end of time. He’s there because he failed to bring the Devil a Wii for Christmas.