I received this message from Ning dated 9 hours ago and don't know exactly when it will happen but thought I'd let you all know.
I wanted to write and let you know that one or more of your Ning Networks will be affected by some performance-related maintenance we are performing starting at 5PM Pacific Standard Time. We will be moving a batch of networks to a new, upgraded server. During this maintenance your network will not be accessible and will display a branded maintenance page. This migration should last from 5 to 30 minutes, depending on the size of your network and the amount of content.
If you have any further questions about this please let us know!