how it's supposed to look for FOR EACH loop?
public static void usunUrodzonychLatem(HashMap<String, Date> mapa) {

     for(Map.Entry<String, Date> para : mapa.entrySet ()){
         if(para.getValue ().getMonth () >=5 && para.getValue ().getMonth () <= 7){
             mapa.remove (para);
         }
     }

 }
like that?