When you say "from gmail" I assume you really mean "to Google Calendar" -- I can't imagine what else would make sense in this context.
There have been some reports of dates being incorrect (off one day) for all-day events that are synced to third-party calendars such as Google Calendar, but none of those reports came from the Mountain Time Zone, where you apparently live.
When you say "incorrect," do you mean off by one day, or more than that? Are times off as well? Which direction are they off? Does this apply to all-day events, or timed events? Are other events correct?
Questions that can benefit the larger community should be asked in a public forum, not a private message.