I don't think I've ever played in a game where time was forcibly pushed along (so to speak). Generally, the way I see it, whatever day you're creating a post (not a comment), that's the day it's happening on. So it's important in the top of the post to give some idea of when in the day it's occurring, but I wouldn't also expect that all RP within that post has to finish within that day. Might take a few days, if posters are on very different schedules.
Now, you wouldn't want it to take too long, because it will be difficult to put that character into any following situations like...
Say Diana is in a thread with Jack on Monday and the thread is stated to be taking place late in the afternoon and I also want Diana to go to another thread to talk to Bill later that evening. I can't
really start that second thread until the thread with Jack is wrapped up (now, if the thread with Jack isn't hugely consequential and likely to change the tone of how she interacts with Bill...I could probably get away with it, especially if I've talked to Jack's player first to make sure Jack wasn't going to spring something crazy on Diana).
And there also might be a situation where, say, I am not at home all day (like yesterday, hah) so I can't make a post on that day, but I need to create something that had to happen on that day. I can still post the next day, and just make a note in the time (don't actually backdate it, just put it up top, like you see on Bill's post in
metempsychosis as to what day it's actually happening and where it fits in to the storyline. This would also work for folks who might post transcriptions of chat logs (which are okay to post, but ideally interaction should be happening in the community).
Does that make sense?
Basically, a day is a day, as far as the date-stamp on a post goes. But backdating and slowtiming happen, so we make allowances for that.
Of course, if, as we go on, folks have a better idea they want to try out, I'd be open to seeing what we can do.