How do I set the time zone on my Sharp SPC384D Atomic Clock?

A couple of years ago, I bought a Sharp SPC384D bedside alarm clock, which gets time signals from the NIST atomic clock in Boulder, Colorado, which is THE legal standard for time keeping in the US. Recently, I had to change the batteries. As you might expect, the current time and date were wiped out when I did so. Once the new batteries were in place, I was able to reset the time and date without any real problems. I was not able, however, to reset the clock for the Central time zone, which is where I am living. I've lost or mislaid the instructions for this silly thing, and I can't find any kind of website or online information about this clock, except where to buy it. Does anyone have a copy of the instructions for this clock, or can anybody tell me hoe to reset this clock for the Central time zone? Thanks in advance!