At least for New York City, this is right around the time when the regular school has ended and the summer school sessions are about to shortly begin. Kev and Jack talk about their thoughts and experiences with it in the NYC Public School system. 

(Sidenote: The movie named Summer School is briefly mentioned in this episode and the day after recording, the director of that movie - Carl Reiner - passed away. R.I.P to a comedy legend!)