While the Viewpath Application does not currently have a method of creating a personal calendar for each of your resources, if you need to know when people are scheduled for vacation, why not use the Cross Project Resource Allocation tool?
Simply create a project called "Vacations" and add Resources who will be on vacation in the coming weeks.
Create a Task called "Vacation, set the Start and Finish dates, then add a Resource as being assigned to that task.
When you are looking at your Cross Project Allocation tool, it will be simple for you to see if one of your Resources is on vacation during a given period and you can avoid assigning that person tasks while they are scheduled to be away.
Click here to learn more about the Allocation tool.
Here is a sample Holidays - PTO - Training - Hotline coverage project:
Have the Holidays project open as an active tab across the top, and open other projects you want to report against. The Holidays assigned to resources will show up here, and you can quickly see if there are issues.