A database migration is scheduled for the weekend Aug 19-Aug 21, 2016. It involves a migration to a newer database infrastructure. As a result, any changes made in the migration window will be reverted to Aug 18, 2016 11:59pm.
A network maintenance window is scheduled for Fri Apr 1, 2016. From 8am CET to 3pm CET, access to apps might be either interrupted without notice or not possible.
A data center maintenance window is scheduled for Fri Dec 4, 2015. From 8am CET to 3pm CET, no access to apps will be possible.