Someone that constantly posts what day it is on Facebook. This is usually done in a tiresome or annoyed manner, & often related to the number of remaining days of the workweek.
Jen: I hate Mondays! Friday can't get here soon enough!
John: Jen, you're a real Facebook day dropper.
Suzy: What??? It's only THURSDAY?? Dang.
John: Ugh, again! Stop being a fb day dropper.
Brian: Tuesday done. Three more days until freedom...
John: Yes we get it Brian, you're a real Facebook day dropper.
Mary: It's Wednesday? Hurry up Friday!
John: Shut it Mary! Don't be a Facebook day dropper!
A person, usually overweight & out-of-shape, that always posts on facebook when they're working out (& often exaggerates their accomplishments).
John: "Just finished 5 hours at the gym."
Brian: "You Facebook exercibitionist! You've never even looked at a gym for that long."
Matt: "Just ran a marathon in 2 hours."
Brian: "That'd be a record for someone your size, you Facebook exercibitionist."
Jen: "Off to do yoga, then on to insanity cardio & P90X."
Brian: "I know you're trying to attract a man, but don't be a Facebook exercibitionist."