I've never had a situation where I didn't have to leave a cat or cats alone for the span of a workday. Pretty typical is our current situation, wherein we each go out between 8 and 8:30 in the morning; I'm home anywhere from 5:30 to 7:30, depending on when I get out of the office, and what I need to do on the way home; Rob's in somewhere around 7 or a little after.
I have always left at least a couple of radios on. That's about security as much as anything, but I think it's company for the cat/s, too.
Remember that cats are nocturnal, and sleep a good part of the day. I make sure I say goodbyes in the morning, and say something about how long I'll be and what I'll be doing. Do they understand the detail? No. But that's not the point. They do understand the "keeping them in the loop" I think, and that this is just a normal day that they can sleep through, and we'll get our cuddles later.
Sometimes they are all over me when I get home, and sometimes they aren't finished sleeping and resent being disturbed
I just play that one by ear, and everyone's happy.
Don't do too much of a number on yourself -- they can do that quite satisfactorily without help