Where did this name come from?

Black Friday? I ask you all...have you ever heard that term before 2 years ago? I mean, it's like it sprang up out of nowhere. The same goes for "Cyber Monday" (which is today, by the way, so I wish you all the best in this, the traditional Cyber Monday season). That one I can forgive, because online shopping and merchants caring about it is a relatively new phenomenon, but people shopping on the day after Thanksgiving is a longstanding tradition. But, it was always called "the day after Thanksgiving" not "Black Friday". My issues with the term are twofold:

1. It's like giving yourself a nickname. (i.e. Micheal Jackson, he's not called "The King of Pop" as he decided he should be. He's called "the self-proclaimed King of Pop" or by the more honestly come by nicknames like Wacko Jacko...) I realize that these sobriquets have to start somewhere. I'm not opposed to coining new terms, per se. What I object to is everyone acting like this is not a new term. It's like someone using the term "bling" back in the late 90's, then being all like, "what, that's been a thing forever. You've never heard that term before? That's totally how Marie Antoinette referred to her jewelry..."
2. You can't just take something that has historically meant something bad and change that meaning to the exact opposite. Black Monday has already staked out this territory, and that is known far and wide as an extremely bad day. (I was just thinking of the stock market thing, but there are also all of these...who knew? Also, please note...all bad) Yet we're supposed to infer that while Black Monday is bad, Black Friday is somehow good? (Also note in this list, one good...many bad).

This rant actually has no purpose other than I've been hearing the term relentlessly for days now and it's been bugging the crap out of me. It's at least out of my system for another year I guess.