Even with the best planning and preparation, mistakes happen. Scheduling changes for periods of low activity is a way of minimizing the impact of unexpected outages. The Change Management Board has recommended standard maintenance windows in an attempt to guide changes to low-use times as a way of minimizing the impact of expected outages. The time frames recommended are intended to provide an opportunity during the week and a larger window over the weekend.
Changes should be performed during standard maintenance windows. Changes can be scheduled anytime within the maintenance window as long as sufficient time is allowed for recovery—they don't have to start at the beginning of the window. Changes can be performed at other times, but it should be a conscious decision with justification. Suggested maintenance windows are:
12:01 to 7:00