impl: ldp toString - date and timezone display

assignment/src/main/java/appointmentplanner/LocalDayPlanImpl.java

@@ -109,4 +109,9 @@ public class LocalDayPlanImpl implements LocalDayPlan {
     throw new UnsupportedOperationException("Unimplemented method 'nrOfAppointments'");
   }
 
+  @Override
+  public String toString() {
+    return String.format("Day: %s, TimeZone: %s", day.date(), day().zone());
+  }
+
 }