P6 8.3 Web - If a resource is assigned to one global calendar and a project is assigned to another,

We have discovered that resources assigned to a project activity(s) is the wrong calendar. Now, there are no resource dependent activities, but I have concern over changing the resource's calendar as they may be assigned to in-progress activities. My thought is that while the project is using one global calendar and the resource is using a different global calendar that the available work and non-work may screw up the schedule?

Thanks in advance!

Bob