How do I restrict Change Request planned start dates based on a Blackout schedule?

[Bill7]

We would like to eliminate the ability to start a change with an incorrect planned start date.  So far I have not seen anything out of box to do this and am currently thinking of generating a Business rule.  Am I looking at this incorrectly?

[Mike_R]

You can configure your blackout schedule here:

instanceName.service-now.com/cmn_schedule_blackout_list.do?sysparm_query=&sysparm_view=

User will still be able to create/submit the change request but it will show up as a conflict and say Inside Blackout window.

If you want to prevent this, then yes, create a custom business rule.

Alternatively the CAB can just reject the Change, and then people will learn real quick not to schedule a change in a blackout window! 

[Bill7]

The problem is simply that the conflict gets ignored and despite multiple changes being denied as well as multiple emails people aren't stopping.  Thanks for the verification on how to process that, though