We personally went during the July Mays session in 2019, which was around 18-23rd (I don’t recall the exact dates). We chose that session, due to conflicts in June. It was far less crowded then the May & June NSC’s, we loved it! My Mays girl, and the rest of the Mays group registering with her, all registered for class in under 3 minutes, getting every class they needed.
They DO open up a certain number of seats in classes at every NSC (except August, you’re not guaranteed during that session, some classes will absolutely be full, or only 8:00 a.m and 5:00 p.m. sections open). So people who tell you, you HAVE to go to the 1st NSC are just wrong. The first couple May & June sessions tend to be crazy hectic, at capacity, unorganized and you can guarantee the system will crash at some point. Those dates work best for some, I get it.
I will say, having a later NSC was nice-for us-it gave us time to totally get past high school stuff, and focus fully on college. She was 110% ready for college at that point. AP scores were back by then, too, so they could discuss & accept/or wait on those.
There is no set date when sessions fill up. But when they’re full, they’re full. I wouldn’t suggest the August NSC , there’s just a lot going on then-Fish Camp, Impact Camp. sorority rush, dorm move-in, Howdy Week. And your schedule could be pretty limited.
I also suggest don’t scheduling the May NSC if your kid hasn’t even graduated or had prom yet. They need to be completely finished with high school.
Don’t bring siblings! It needs to be parent(s) and incoming Aggie only. If both parents are coming, register and pay for both, there are meals and seats in Rudder are limited. There are no refunds, and can be difficult to switch sessions the closer it gets. Schedule the NSC and keep that date, as the focus of your summer, plan around it.