what year was grandma got run over by a reindeer

That's a tough one! I'm not sure if the song is based on a true story, but the lyrics suggest that Grandma was probably running away from the reindeer when she was struck. So it's hard to say exactly when the accident occurred. Maybe it was during the Great Depression in the 1930s? Or perhaps it was a more recent incident? I'd be curious to know the answer to that question as well!