Did you know there's a difference between GMT and UTC? I didn't. I haven't found it stated succinctly on the web, but it has to do with leap seconds and the increase of them due to tidal deceleration. Tidal deceleration is like how it is difficult to move a big tub of water around due to the inertia being in liquid form absorbing energy. The point is, I needed to change the timezone on some servers and here are my notes.
/bin/rm /etc/localtime /bin/ln -s /usr/share/zoneinfo/UTC /etc/localtime /usr/bin/vim /etc/sysconfig/clock # The ZONE parameter is only evaluated by system-config-date. # The timezone of the system is defined by the contents of /etc/localtime. ZONE="UTC" UTC=true ARC=false
While you're at it, you should sync the time and make sure the clock is set on the hardware.
/sbin/ntpdate /sbin/hwclock --systohc