I know plenty of friends (mostly medical) who've had "on call" shifts on top of their 9 to 5, but in those cases it was pretty exceptional for them to actually

I know plenty of friends (mostly medical) who've had "on call" shifts on top of their 9 to 5, but in those cases it was pretty exceptional for them to actually receive a call, and the "interruptions" would be a small number of hours.