I never used to set times for my staff.. they used to please themselves
However, if they had a problem they always used to vent it to me.. which I prefer rather than someone talking behind my back
If i was you I would talk to the boss... he is not gonna fire you... in fact he is prolly gonna appreciate you talking to him.
Tell him you would like to take a break outside... he knows that if he says no that he is breaking regulations.
There is a regulation.. but I am not sure what it is.