All BPS log file and DB timestamps are in GMT time instead of UTC time. UTC is probably the better standard, but it came down to picking one and GMT was chosen.
I think what you are probably really asking is how to change your timezone for your particular site. Go to the WordPress > Settings > General page and choose the timezone that you want to use. BPS will use whatever timezone you choose and timestamps will be relatively adjusted to the UTC or GMT time setting that you choose.