Lots of pertinent details can be gleaned from posts that aren't anonymous by checking a user's FB profile and past group post history. If they want real privacy they can lock their profile.
Typically 3 months of 500K+ embassy specific, that being said sometimes they ask for 6 months of bank statements to get an idea of your financial stability, but that doesn't mean the 500k has to be in for all 6 months.
I don't know what to say other than this must have something to do with an early check in time, for instance I don't think you're going to be let through passport control before midnight if you have a 4:00 a.m. flight. Regardless my understanding is it's always been the time you stamp out.