Without a scheduled time its just very annoying to organise anything you have to set a time and adjust based on the numbers online that are availble if people cant make it for say 7pm then they just have to announce it on the forums or poke someone ingame, if we use the addon that was mentioned a wile ago they can add a note saying -I wont be around for x time then the organiser knows that and can arrange a backup player based on the signups and then swap players around during the evening thats the most fair way i can see.
Oh and a note if we cant start earlier i might as well resign from raiding straigh away there has to be a way we can work around where people are availble and not just base it from UK time even if it means afk moments for some people for personal matters we can still adjust that with either a break or swap people around but start at 9pm UK isnt fair for people that lives in +1 +2 zones even if it is weekend.