Yeah, that's definitely it then. In the US we call things shift work of you have a shift. Which are things like, show up at 2 PM, leave at 10 PM. It's typically reserved for jobs that relieve other shifts. So showing up late means your coworkers have to work alone for a bit. Something like an office (not call center) wouldn't be considered shift work here because you're generally not directly interfacing with customers or relieving people from a previous shift.