One of the unwritten rules for the GESB.... It's NOT formulaic in any way. Time in the bar has absolutely no relation to how many posts there've been or to real-life time for that matter. A day can last five hours or two weeks or a month. It can span fifty posts or five-hundred. Trying to fit the bar into a formula is like trying to fit a sphere into a square-shaped hole, it just doesn't work. You may think it sounds odd...but if you take a look, it's worked for 1200 pages thus far, which is much more substantial than any of the other RP's I've seen in the Animorphs section or anywhere on the site for that matter. Granted I don't visit non-Animorphs RP pages really ever, but you get my point...it works.
I concur with the others, don't try to guage time-passage, just have your character do what he needs to do. And a quick word on spin-offs. Our general rule involving spin-off threads is really pretty simple. If there's going to be meaningful interaction between multiple characters in a location that isn't in the bar's planetoid atmosphere then it warrants a spin-off. If it's only a couple solo posts or is actually in the bar's space (i.e. in the bar, in a landed ship, in the ship graveyard, in the forest, by the lake, in a ship flying around in the atmosphere, etc...) , then no spin-off is required.
Also replaying FFVIII atm. Sig pic is /win.