On my 48SX it's a simple matter to add or subtract a second from the display time. On my 48GX the pull down menu makes this klutzy and difficult to set closely. (On the whole, I do not care for the pull down menu approach to soft key commands on the 48GX. It seems klutzy and like a step backwards from the 48SX's displaying soft key commands at the bottom of the display.)
On my 48SX I can also advance the clock by entering "n CLOCKADJ" where n equals 8192 ticks per second. Does "CLOCKADJ" do the same on the 48GX, and if so, what is the tick rate? Is it still 8192 or is it faster?
On my 48SX I have a simple program 'KORR' << n CLOCKADJ >> which is executed by the alarm function at 2 AM each day. By judicious choice of n I can correct for the clock running slightly slow. (Left to its own devices, it loses about a half second per day.)
(Wife says I'm nuts for trying to keep all the clocks and watches set so closely, but it compensates for my otherwise disorganized life.)