Legal Question in Employment Law in Washington

Re: new job

Doesn't look like anyone ever answered your question, so I will at least put something down for you.

Being on salary does not mean you are on the clock 24 hours a day. If you really have to be "on call" at all times you are not at the store, if you really are being prevented from conducting your other normal activities, it is possible that you are entitled to additional pay for that. (More details about just what is expected of you are needed.)

If your boss wants you to actually be at work during the hours you would be in school, you may not have any options. However, if he or she just wants you to be "on call" but doesn't otherwise want to pay you for that time, perhaps a compromise could be worked out in which you carry a cell phone with a silent (i.e. vibrating) ringer, so that you can attend class.

Something which is unstated in your question but may be an underlying misunderstanding; just because you are "on salary" does not mean you are "exempt". If you are exempt, you are not entitled to overtime. To be exempt, though, you have to be able to make supervisory decisions. Normally, you would have to be able to hire and fire people and make other decisions regarding their working conditions. If you do not have that authority, then you are not "exempt", which means that even though you are "on salary", your employer still has to pay you overtime (at 1 1/2 times your pay rate) if you work more than 40 hours in a week.