clockskew

Returns the clock skew in seconds between a given nameserver and the local system. Skew is returned in seconds, a positive number indicating that the nameserver time is ahead of the local system, a negative indicating that it is behind.

It depends on the dig utility to perform a TSIG query


./clockskew nameserver   

Source code:
clockskew.pl

Feedback to dave@knig.ht is appreciated.