I already add one culture for the catalog. But we still can't get the responding time?
See image:
You correct, the time shouldn't be displayed in GMT, but in local time. We tried to fix it in most places, but some still remain. It will corrected in the upcoming release.
This has been now fixed in 1.11 release.
Dates format have been changed to local time in Reviews and Orders lists. You can get the latest source from github or upgrade to official version 1.11 as it has been released.