While The Twilight Zone does have a more suitable episode for Christmas, "The Changing of the Guard" is another Christmas special that works a whole lot similarly to It's a Wonderful Life. It also stars Donald Pleasance, which makes it all the more fun to watch - you can have him both at Halloween and at Christmas!
"The Changing of the Guard" is a rather low-key episode, and that makes sense because of the Christmas subject matter. It's not an intricate episode, nor does it attempt to meld science fiction into its scope. Instead, it presents a life lesson, and a theme of worldly interconnection, surrounding an older professor who has just been asked by the headmaster of the school to retire.
That's Donald Pleasance, in all of his proper glory. Even in this episode he looks incredibly old - bookish, dainty, and absolutely grammatically correct. It's difficult not to like his character, Prof. Fowler; he might be a bit antiquated, and wholeheartedly immersed in his studies to the point where anything besides poetry and literature is foreign to him. Still, he's a good-natured man, and the extended introduction depicting him in his classroom cements the feeling that he's a great professor trapped in his own rut, unable to get away from teaching poetry that has lost relevance.
"The Changing of the Guard" moves very slowly, but Pleasance carries this episode. With someone else in the shoes of Fowler, the episode might have felt like a snail's crawl; but watching Pleasance's face, alternating between a deep depression and manic throes of joy, makes this episode worth the watch.
It does take a while to get to the point though. Fowler contemplates suicide after agreeing on his resignation. In a way, he feels like whatever he taught his students became useless after they left his classroom. Struggling with a sense of purpose, he stumbles out into the snow, where he's taken back to his classroom with many of his former students, all of whom have died in some terrible tragedy.
They relate to him his importance - ridiculously explicitly, I might add, even coming out with the exact way that Fowler changed their lives. It doesn't work as well as if "The Changing of the Guard" were to take Fowler to maybe two or three people and show him exactly how his work influenced them. It comes off as surprisingly obvious in an episode based on literature, citing old poems with lingering metaphors while putting its entire meaning on its sleeve.
So in a way, "The Changing of the Guard" doesn't work well as a Twilight Zone episode. The best ones are when the characters and the audience realize the meaning implicitly, the theme coming as a shocking, but quiet, twist. This one blares it out for all to hear - "look at the amazing things you have done!" - and it suffers because of its obviousness. It's also an incredibly naive episode; all of these dead men have been directly influenced by Fowler in some way, but in reality it would hardly be the case.
But the presence of Donald Pleasance is enough for me to add this to my holiday viewing. While it might not make anyone's top Twilight Zone episode, it's a simple enough affair with a heartfelt message, even if it is shouted at you like Santa Claus proclaiming a merry Christmas in the night sky.