@Arkandel said:
Is it efficient enough to tell people "this is when I can be on, talk among yourselves and tell me when you want the next scene ran"? Is it more or less fair than that to start the next scene with an +event at some time convenient for the ST and whoever can make it may come? Or is it reasonable for players to expect the ST to go a step further and organize them?
I feel like it's reasonable to ask players when would be best for them, to try and work around their schedules if they communicate them to you, and to use web-based scheduling tools (I like When Is Good? and Doodle.com) if there's enough buy-in to make those worthwhile. I don't have much faith in players' ability to organize themselves, but beyond that, I do feel like as the GM it's your job to cat-herd to some degree. Unfortunately.
If you ask these things and players don't tell you them (or can't because their schedules are too ephemeral), meh, stuff happens when it's convenient for you to make it happen and people show up if they can, or don't. I don't wring my hands too much about it if they can't, if I feel like I've made a reasonable effort. That's the only way to stay sane.