We have the schedule now, Vintage events at 5:30 on both Saturday and Sunday.
Edit: Possibly Friday at 5:30, but there's a typo of some kind there. It says Vintage, format Standard at the moment.
I got at them about that on Twitter and it should be fixed now.
I'm a little annoyed at the timing. Each day's Vintage starts right about 2 rounds into each day's Legacy and Legacy pays down to x-2 so even winless legacy players will have to make a decision between potentially prizing and dropping to play vintage.
I would say it can't be helped but I don't see any reason that the daily legacy events can't start another hour early. Oh well. I'm planning around $150 just for side event entry fees at GPHOU now lol