[peterwwillis]

In the United States you can work pretty much indefinitely as long as there aren't specific regulations against it like for truck drivers.

Part time NOC gets six to twelve hour shifts as needed, and you don't need them 24 hours, you only need them during non office hours.

Weekends are the only time they're there 24 hours, and usually one engineer, developer, devops, *admin, manager, etc rotates out a shift so they have to be familiar with how the system works in case someone gets sick or takes vacation.