I accepted a salaried position with a six day work week. Although I am employed by the same owner as other managers, I am the only Manager working at a retail store. The other Managers work in the Corporate Office, unrelated to my position.

All Managers are required to work 6 days but occasionally the other Managers take a second day off but I am not permitted to without having my vacation time being deducted.
Does the law change because I am in retail and they are not.

How many hours must I work each week, 48? If this is so then as long as I work 48 hours shouldn't I be able to take a 2nd day off. I was also told that I get the major Holidays off, but then I have been told to work. When I take a 2nd day off, I am required to fill out a form when my vacation time is deducted.

Is it legal to make a 6 day work week for salairied employees. If so, then it should be across the board, right?

Welcome to salary and management, How many hours must you work, and that answer is ever how many that the company tells you, that you have to work, 48 is a easy week for most of managers, most work closer in the 60 plus hours a week,

A person on salary can be told to work a 7 day week, again welcome to management ( they won't do it all the time, but there will be weeks, you have to work all 7)

And yes while you get holidays, you may have to actually work the holiday but will normally have to take someother day off for that day.

And "accross the board" also welcome to management, some departments have other hours and requirements

You may wish to follow up if one set of management is given time off you are denied, but short of filing a law suit when you are denied ( which of course will cost you your job) there is not much you can do except complain to upper management