Have you looked at the Server Clock Drift (PowerShell) and Server Clock Drift (Perl) templates?
Component Monitors
Clock Drift (Internet Time Service)
This monitor shows the clock drift between the target client (target node) and the target Internet Time Service server (argument) in seconds. Positive values of clock drift in the message field indicates that time on the target server is running faster than it should. Negative values indicates time on the target server is running slower than it should. This monitor also returns the current time on the target server.