Actually, no.
At my companies we always scheduled computer upgrades and programming updates for times when it impacted the majority of our customers the least. With a majority of customers coming from the North American. time zones the scheduling as it is makes sense.
If it's a company that operates 24/7, such as this, responsible management calls for the IS department to be staffed 24/7 in some way. Beyond that, employee schedules can be adjusted so that no overtime is required.