On December 8, 2016, we'll be upgrading FogBugz On Demand to version 8.16.906. We will upgrade accounts gradually from 1000 ET to 1900 ET. We do not expect any downtime during this window.
After your account has been upgraded, at your next local midnight, your account's database will receive a schema upgrade. You may see a service interruption of up to 5 minutes when this occurs.
Edit: we are moving the deploy back to the 8th. The version will still be 8.16.906.