It's a rave?

First of all, they did not look like teenagers going to a rave. They looked at least 24 years old. They were not dressed like they were going to a rave, they were wearing Nike sneakers and nerdy clothes. They looked like they were going to dinner at the Olive Garden. Furthermore, it was my understanding that raves were held in some random place like a warehouse from 11 p.m. until dawn. I thought they were drug filled dancing parties. This "rave" was held in mid-afternoon to early evening like a festival. The premise is ridiculous. Why not just say some 20 something people were heading to a weekend rock festival only to encounter crazed zombies. I would've bought it better that way.