We are going to begin running the automated Windows Server Update Services on the last Sunday of every month. This affects all the servers that run Windows O/S, which includes almost all of the customer-facing servers (web, SQL, Mysql, etc.).
We have previously let the update service run less frequently, or when there was an important update or hotfix, but running the updates monthly should make for quicker updates overall, and a more consistent maintenance schedule.
During the windows update, a reboot may be necessary depends on what is done on the servers.
We can't say how long the windows update will take, and some times there may be no interruption at all.
The potential disruption depends on what Microsoft sends out to the service.
And we want to make you aware of that to avoid any surprises.
We serves customers worldwide, so unfortunately there is no ideal time to perform updates.
We base the monthly maintenance window on the point that traffic on our network is at its lowest, and that is Sunday from approximately 1:00 AM to 5:00 AM Pacific time.