OK, after talking to AppleCare here is what fxed my problem: Reset all Settings, restore as a new iPhone. All my apps and music are still there, but it fixed whatever caused the time zone setting to keep moving to Chicago.
Very weird software glitch, but an easy fix.
Hope this helps out others who experience this.
Thank you. I was having the same, odd problem...but only after the recent change to Daylight Savings Time. The fix that you (via Apple Care) suggest ("Reset All Settings") for my iPhone 4S worked. Of course, it did mean that I had to update my Sounds, e-mail Signature, etc. from the Default Settings (a consequence of the Reset All) back to the way I had customized them. Fortunately, I did not lose any data implementing the fix, and I did not have to re-synch my e-mail or anything else as far as I can tell. In total, it took about 5 minutes.
I didn't like the reset everything solution; I found this article which was much more useful:
For me it was an easy thing to fix; I had the timezone setting disabled. This is in Settings > Location Services > System Services (right at the bottom) > Setting Time Zone - make sure this is enabled.
I still have the problem. I had to reset my entire OS on my computer via instructions from the Genius Bar, and reset my brand new phone to stock, and the clock still sets to Cupertino time. I'm in a major business hub city, Phoenix, and I have to set my clock manually because when I have it set to "Set Automatically" it always jumps to thinking I'm in Cupertino California.
(Apple's version of Maps also thinks my address is in Brazil though too)
Since upgrading to the new **** IOS 7+ My iphone as been nothing but trouble.
I've repeatedly restored the iphone to try fix the WIFI issue a lot of people are having..
NOW I find my iphone is time-warped back to 1970 the year i was born & I can Not change the year.
So Now that's 2 problems I've got ..the wifi & year & Date. It seems that upgrading to the Troublesum IOS 7
as been somewhat of a Massive downgrade & now made my Iphone totally useless & just like any other crap phone out there.
But OP thanks for this work around I shall go try & see if it works now..