I have ready some of the posting on upcoming event, and i though it takes the format from the configuration menu. But for some reason my two events that are schedule for 2011 have wrong time on that the dates are oky but it added an hour to the starting time, i have check the event time and i have not found still why this is happening.
Check your time zone settings in BOTH the Joomla global configuration AND in the JEvents configuration. If those are both correct AND you have the latest version of the DT Reg component and module, you should have no time zone issue.
I made the timezones the same but its funny now. I have the upcoming events listed on the right side on every page, but on the event listing page it add an hour for the event that schedule next year, but for the event that's scheduled this year the time is correct. But when you click on the detail page ( i have used the article ) the time on the upcoming event is correct, i don't know what's going on with that. Also i cleaned my cache just to see if it would make difference.
Also i tried creating the event again so see if this error went away.