Last year they posted the start time on their Twitter site about a day before the deals went live. (5 AM Eastern if I remember right.) A few things did sporadically go on sale before their official start time, but not long enough for them to sell out early.
I recall things starting to go live at Midnight PST but the majority was 1:30-2 AM PST.
I'll second the order as it comes available. It's free shipping anyways so don't try to do everything (doorbuster/big items specifically) on one order or you will end up with an OOS. Plus that means more packages anyways, and who doesn't like getting packages in the mail.
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