IT WORKS !!!!! I let my battery completely die and left it for about 2 hours before charging it. I did not turn my phone back on until it was fully charged. Not only have I not gotten a "Unable to determine current Time Zone" message (which I was getting several times a day) my "current area" message on the weather has been replaced with the correct location I am in!
i "lol'd" at this lol
also im wondering if by letting the battery fully croak off its the same as pulling your battery for a few minutes and draining all the juice out of the phone itself before putting it back in and powering it back up. the power cycle option they have wouldnt do this. it would basically be like pulling your battery quickly and throwing it right back in.
Yeah, could be acting like a capacitor and holding the charge for just long enough.
Whatever works I say. If this turns out ot be a fix, then HTC will need to probably tweak the SimPull to correct issues like this.
Keep playing with the phone, see if it continues to pop up over the next couple days. If it does, see if Sprint is working on towes in your area or if something is wrong on the network. If that checks out, try the suggestion above and see if it cures it. The fact that you haven't had it before makes me think they could be doing work on the towers in your area or something else is going on with the network in your area. Otherwise, you would have probably had it from day one as others have been mentioning. But not impossible.
If they are doing work in your area, then the above mentioned battery deplete probably won't make a difference.
I've been having this problem pop up occasionally too, though today it keeps happening after I clear out the notification. I also noticed my time/weather widget listed my location as just "current location" lile one of the previous posters said. Instead of draining my battery, I just tried the simulated battery pull by holding the power button for 10 seconds. It's too soon to say whether the "set current time" bug is fixed, but I now have my actual current location listed by name in the weather widget, so I take that as a good sign.