The trick with planned downtime is to carefully plan it :). There are a lot of services, which don't have to be highly available 24/7 (of course there are also

The trick with planned downtime is to carefully plan it :). There are a lot of services, which don't have to be highly available 24/7 (of course there are also some which do). Planned downtime means to put the downtime into a time slot, at which there is the least customer impact. For many services, it is possible for the customer to adjust usage to it easily. This doesn't mean, it is generally ok to be down, just because it was announced in advance :)