Not only that but if you have a multiple continental team then no one needs to be waken by an emergency meow. (My PagerDuty is set to a meow sound. So we practice meow driven development: I don't want to hear my phone meowing piteously.) Say, you have someone on the US west coast they can do 10am-10pm while someone else in continental Europe being nine hours ahead can do 7am-7pm.