A number of times a year, announcements are posted in communities, to tell there is a scheduled update, upgrade, maintenance or fix planned, with no details.

About 8 days before the actual scheduled process, the time table is published. To make sure users take correct actions to save their files and work. And to notify during this period parts of the purchased applications do not work.

So it would be fair to publish this schedule for a year upfront, to see and plan when we can't use the purchased applications. In Europe the time of maintenance sometimes takes a complete day.