Sony has not confirmed what time of day PSVR 2 preorders will go live yet. So if you're still up around midnight ET tonight, it will certainly be worth a quick look online at the PlayStation store. In all honesty though, it might end being anything from 3am PT, or even at some point in the afternoon.
That's why your best option (aside from sitting there refreshing your screen all day) is to register with Sony and cross your fingers that you get a preorder invite emailed to you.