Weekdays are better for me, I wouldn't start any earlier thsn 8:30 eastern (5:30 pacific) or it'd be tough for the west coasters to make it. Another option (if enough people are interested) would be to do a separate west coast and east coast series with the top season points drivers having a championship race at the end. Obviously you wouldn't have to live in the region, just go with the start time that's best for you.