The Simple FACT is
You should only be expected to work your Regular Shift hours. It's not practical for every business to work 9 to 5, Monday thru Friday.
If my internet provider needs to upgrade their system, I want it done during off peak hours so it doesn't interrupt my business. I'm not taking the day off work to go to Disneyland because they are only open 9-5 M-F. That's just ridiculous. I couldn't even buy gas on the way home because all the gas stations would be closed, "It's after 5, the employees had to go home."
There are plenty of reasons not to work 9-5.