If there's a problem, you have to log a support ticket and wait three days for a response
I work in a 7-day-a-week tourist / academic business, several sites spread over a large geographic area. We have our own IT department who only work 5 days a week and will not carry pagers or a department mobile for "complicated, historic resons". So if the shop tills go down on Saturday morning, or there's a WAN problem meaning no-one can log on and do work, it could be Monday before they are sorted. Doesn't happen -very- often, but when it does, it's annoying.