AFAICR (it is on loan to a friend) KKSO 3.1 (Wifi only) follows my wireless router's TZ.
I wanted this Kindle to be forced to UTC and it wasn't wanting to do so. I tried to define the router's TZ (and suceeded). Kindle followed nicely.
KDXG 2.5.5 needs 3G turned on prior to a forced menu restart and frequently gets set to Alaska time instead of EST5EDT.
KKSO3G 3.3 always gets TZ locally correct.