Black-out dates for Resources in SS Resource Management tool


My organization is international so having resources in multiple time zones, we operate on a 24-hour clock for many projects. Has anyone figured out how to create a centralized calendar outside of the RM? Also within RM, how can you configure the tool to prevent a resource from being added to a task on their blackout dates? Is this done at the profile level? Is there a an error dialog box that can be programed to show when a resource cannot be added on a particular date?