The trick is not to have the actual phones themselves in the schedule based partition, but in a partition which is accessible by the CSS assigned to your Unity MWI ports.
We have an Admin_PT partition for directory numbers which should always ring and a TeacherPhone_PT partition for DNs which should forward to VM based on the Time Schedule. What determines if the call goes to the phone or to voicemail are two completely different partitions, call it SchoolHours_PT and AfterHours_PT. Its these Partitions that you set a schedule on. And then in the SchoolHours_PT, create your CTI route point with CFA to VM and your matching DN pattern, XXXX for example. Then, in your AfterHours_PT, create a translation pattern with the same matching pattern, and don't do anything else except change the CSS to one that can reach your TeacherPhone_PT.
Next, create a TimeBased_CSS which has your normal, call all of the time partition, in this case Admin_PT, your SchoolHours_PT, AfterHours_PT and any other partitions which you may use. It is *THIS* CSS that you assign to not only your gateway, but also to the majority of your VM ports. I say majority, because you'll notice that the TeacherPhone_PT is not in there.
Next, set aside a few VM ports for MWI notification. You'll need to go into Unity and uncheck MWI notification for the majority of the ports you configured the TimeBased_CSS on earlier. For those remaining few VM ports, you will use a CSS which contains the same partitions as TimeBased_CSS, except replace SchoolHours_PT and AfterHours_PT with your TeacherPhone_PT.
Finally, check the CSS assigned to your MWI setup in CM. Make sure that it can reach all of your phone partitions.
It sounds complicated to setup, but in reality, all you are really doing is intercepting calls normally destined for a teacher partition and rerouting them to Unity. The trick in our case, since outside calls 'originate' from Unity, was to separate the CSS assigned to the VM ports. It wasn't until this thread started that it even occured to me to do this.
John Lever
Telecommunications
Richland School District Two