Having a change calendar that shows when releases are happening in the system is a very valuable tool. This would also be a very good tool to have in the portal, so that people will know what things are coming that might impact them.
Proper change management includes logging a change record for anything that impacts a major CI, especially those that require downtime. Having a way to show the system downtime schedule for a release would be awesome.
The Change Management does require some attention here and this would be a big step in helping other agents keep track of whats out there that might affect them directly. Would be nice to have the Change "Planned Date" to alert agents that a change is about to take place, such as 24 hours in advance.