The Hundred-Year Christmas - Signed

This is a novella that has different meanings, depending if you're a child or an adult. It's about the poignant friendship between Father Christmas, who lives a hundred years before being replaced, and Father Time, who lives only a single year before being replaced. Each year, Santa sees a version of his friend grow old and die. Now it's Santa's turn, but he's having trouble finding a replacement, and if he doesn't succeed, there'll be no one to take care of the infant Father Time. Time itself will stop.