In reality , its the neighbours that would be doing the counting of 28 days....... if you have no immediate objectors then operate as you like. If a complaint is made to the local council /planners , then you would have to strictly adhere to the 28 day rule.
If any local objectors dislike the idea of an aeroplane operating now and again ( always keep circuits /GAs down to bare minimum ) then point out to them that on each of the 28 days that is allowed ..especially sunny weekend days ..you could invite any number of other aircraft and fly from dawn till dusk and be a right pain in the a*se.