Adjusting time, or not?

After a few years of using a relocation chart (for transits), I came across today (somewhere in this community, and later on a couple of other chat sites) that we're to adjust the birth time for the new time zone! I have never done this and other websites suggest not to (eg, astrodienst http://www.astro.com/faq/fq_fh_reloc_e.htm).

I can't find a definitive authority on this.

Personally (my opinion only) I find this to be highly problematical-however, using a purely symbolic approach I can see that there might be something to it!