Trying to use time zone plugin

I am running Windows 7 64-bit with Stellarium 0.10.6.1.

My question concerns the new time zone plugin. I checked load at startup and then click configure to set it. Switching time display works great. I can set display to 8pm.

However, I do not understand the time zone shift. I am in Houston TX and it is 8pm (sky is dark). I switch from system time to UTC (second option) and restart Stellarium. I'm still in Houston, the sky is bright, but the time is still 8pm. I had thought it would have displayed UTC or the time in London (GMT?) - but isn't it about 3 am in London and still dark? I move to other locations and the sky changes (it's dark in UK) but the displayed time is still 8pm. I try the offset with various numbers - the sky changes but the displayed time is still 9pm (plus a few minutes). I'm in Houston and would like to configure Stellarium so that the displayed time and sky in Moscow (for example) line up. What am I doing wrong or how am I confused? Is there a manual somewhere?

Fonts and text look great and the program is snappy. Thanks.

... a few minutes later ...

I think I have this figured out. If I set it to UTC+2, then that aligns the time with a town in Israel (the one at the top of the list). When I start Stellarium, it still displays the current time in Houston (but the sky is off). When I switch location to the town in Israel (the one at the top of the list), then the time and sky are aligned. :D I just need to know, ahead of time, the UTC offset for whichever location other than my home that I wish to select. It would be nice if the displayed time included a reference (e.g., UTC+2) - but this is still pretty great. Thanks.