I think I can clear this up. What if they're paying less than minimum wage because they're shady and obviously don't give two shits about their employees or customers (which still makes no sense as the only bad person we know about from the company is William)? Scott has apparently said that the pay was intentionally shitty (although he probably didn't say shitty), so it was probably less than minimum wage and after the 90s.
Unless "20 years," is Scotty C.'s retcon, and if Phone Guy was being literal, that would make it 2003, which is 20 years after 1983, when the restaurant opened. However, November 12, 2003 was a Wednesday, and while that's not a weird day to get paid on, that would mean that Mike worked Saturday to Wednesday, which doesn't seem right.
If Phone Guy was being casual and didn't mean literally 20 years, it could've been 2004. Perhaps the place hadn't turned 21 yet, and in 2004, November 12 was a Friday.
I'm sure anyone reading this will just dismiss my evidence and say I'm wrong because Game Theory said so or because they just don't like my theory.
It doesn't have to be the 90s just because of the Chuck E Cheese murders and doesn't have to be minimum wage just because Matthew Patrick said so.
Again, Scott said the pay was intentionally shitty, which means that it was an inappropriate wage.
2004 would also make the MCI many years before and the newspaper that says that would make more sense than 1985/7 to 1992/3.