That's not what I meant. For example, you have a session on Thursday, so why not also create one for the same time on Saturday? 5 days for it to be full up, and you're more likely to find dependable people if you have multiple sessions organising at once.
Also, I know of two others that want to boost WaW, VladimirK and Taillear Dubh, so that makes things considerably easier.
Hey, I don't know how TrueAchievements works, but why don't you set up a boosting session for every 2 days? Or even every day? That way people are given plenty of notice and therefore they know whether they'll be available... Not to mention if there's a session every 2 days, for 3 hours a session, then it'll fly by, hopefully.
So, the question is, can you organise more than one session for the same achievements at the same time?