Well, in the absence of any code or more pertinent details like the OS involved the first guess would be to check that $ENV{TZ} isn't set to GMT in whatever process is spawning your perl program (either your shell or the webserver if this is a CGI).

Baring that, I'd look for any small passing singularities and/or eddies in the spacetime continuum. ("It's his couch then, is it?")