nobody can deny your vacation request unless the written vacation policy clearly states what the policies are regarding vacation the requests. It would have to state exactly what rights a manager has to deny a vacation request. The only one's Ive ever seen be legally enforceable are only when a rep didn't have enough vacation hours accrued. Other than that, it becomes a political issue but not one that would ever stand the test of a courtroom. So, take your vacation when you want to as long as you have the time accrued.