The students take a break during the school day. Typically they are required to go outside and they usually use the courtyard (PS11, CS6, OP12, OP17, OP18, HBP18, HBP22). When the weather is chilly, they tend to huddle in a sheltered corner. A bell signals the beginning and end of break.
On rainy days, however, they are allowed to stay inside and they hang out in a first floor classroom. Peeves particularly enjoys these times, floating overhead and throwing things at students. The kids are so used to this that they automatically cover their heads with their book bags whenever Peeves passes by (OP18).
Harry, Ron, and Hermione have a particular corner of the courtyard where they usually stand:
Harry and Ron waited until break next morning to tell Hermione exactly what had happened; they wanted to be absolutely sure they could not be overheard. Standing in their usual corner of the cool and breezy courtyard, Harry told her every detail of the dream he could remember (OP26).