I have received notification that my virtual server hosting the Teamspeak server needs to be rebooted due to a security update for the virtualisation software.
This will be done on 2016-07-26 during the period 01:00-02:00 UTC/02:00-03:00 BST/03:00-04:00 CEST.
It is expected that the actual downtime will be less than 15 minutes.