From what I've been seeing, January 21st in 1984 was a Saturday. I know it says the 21st everwhere, is that even accurate? Matt's countdown leads me to think the band doesn't consider today to be the date.
Or maybe it DID come out on a Saturday, I don't know.
EDIT:
https://www.facebook.com/BonJovi/pho...4924100337000/
So they posted this on 2018 as Jan 21. Inconsistency or stupidity, we'll see.