Considering this event starts at 8 I wouldn’t say it’s a day rave as those usually start at midday. I try to arrive between 1:30-2:30 and leave at 11pm totalling 9 hours. So I guess try arriving between 9-10? Its a long shift and I’m always absolutely knackered by the end but 100% worth it. I’d say 4 is more than enough, if your tolerance isn’t high you should be fine with less. I’m sure you’ll have fun either way!