Daughter loves sleepovers. She is hoping that every weekdays would be like a small sleepovers and weekends a bigger ones.
Our tour guide at Santa Catalina mentioned that borders are sometimes invited by day students’ home on weekends and day students are often invited to spend a night at the dorm. Daughter found it very exciting.
How does that work in other schools? I hope not to hear that kids are too over scheduled for fun.
The kids are definitely busy but the majority still make time for some much needed fun. Sleepovers on Saturday nights were common at my kids’ school. Friends from other dorms would sleep over in a friend’s room in another dorm, make cookies (or just eat the dough raw most likely) watch movies, gossip, paint their nails, crank call the boys’ dorms. Just typical teenager stuff. Guys do the same - replace nails with xbox and cookie dough with a pizza order. 
My kids’ school was all boarding but we lived close enough that there were occasional visits home with friends in tow revolving around staying up late and sleeping in, eating LOTS of home cooked food, and watching movies. Ot going to a concert and coming back to our house to crash for the night, sleeping in, huge brunch in the morning, and then back to school to study on Sunday afternoon. I’d tell them to bring all their dirty laundry and we’d send them back with clean clothes as well. Fun times.
Keep in mind that most schools limit overnights. For example, as a freshman, my daughter was allowed 2 per term…
At my kid’s school, there are day student lounges in the dorm with beds in case day students want/need to stay over . At first, every night might seem like a big sleepover to new students, as they are suddenly surrounded by their peers 24/7. The ‘lights out’ rule was enforced at her school to make sure the kids get sleep. There were some sleepovers on weekends, but certainly not every weekend.
She barely gets 2 per a term even as a homeschooler. Her friends are all so busy. By sleepover every weekends I meant students get along for fun all day until they go to bed. It sounds like as daughter hopes for. She is going to fly tonight for a 3 weeks-long residential camp. She will get more idea after coming home.