What Are the Must Phone Home Days?

There's actually an infinite list of dumb holidays that you don't know of, right? So it's a question of like, what are the big ones that we can actually agree on? And I can't think of any real major holidays that I would fold my arms and go, no, that's ridiculous. Do you phone your parents on their wedding anniversary? It doesn't feel to me like that should be a required, like along with a Mother's Day,. But what do you think about that?