Dear Wayne,

First read this section – http://www.spheretester.com/user-guide/#Events_Display

Then in order to know GMT offset, I would recommend you to go through a link to understand better – http://www.profitf.com/articles/forex-education/forex-broker-server-time-gmt-offset/

And then, if you have any confusion I am here to help you.

Cheers,
Aayush