I have been working for my company for awhile now and up until recently I was pretty autonomous. During that time I was producing great results that the majority of people were impressed and pleased by.
I have not been working traditional office hours to minimise disruption to other employees i.e. coming in at the weekends or hours early to get things done. In addition I usually head to and then work from home in the afternoons as it is more productive than being in the office.
Now I have a boss, who just started at the company, and they are trying to use the following paragraph in my contract to insist that I be in the office 9 - 6 Mon - Fri, be on call 24/7, still go into the office out of hours regularly, including weekends, while maintaining my current level of productivity and without additional remuneration:
Normal office business hours are 9:00 a.m. to 6:00 p.m. Monday through Friday, although, these hours are subject to change. As an exempt employee, you will be expected to work additional hours as required by the nature of your work assignments.
What is the best way to push back against this?
EDIT:
The linked question is not a similar situation. In that question the OP was under skilled for their position, their bosses were unhappy with their progress, and the company had an OT (overtime) culture.
In comparison my skills and abilities are not in question, the senior employees were very happy with my progress and the results that I produce, and the company does not have an OT culture (I'm pretty sure that I would be the only one this is expected of).