I've also had people tell me "if you aren't working 12+ hours a day (for ms and hs), you aren't doing your job". That also included skipping your lunch and conference period to "make it work".
Also, it is against the law. You are by law required to have a lunch and conference period. However, i'm not sure of the exact details but its something like that.
I would have a serious conversation bout it with your HD and if he is not willing to change, I would consider talking to an administrator.