You need to upgrade your Flash PlayerThis is replaced by the Flash content. Daylight-Saving Time is not in effect. The Eastern part of South Dakota is in the Central Time Zone in the United States. Central Standard Time (CST) is 6 hours behind Greenwich Mean Time (GMT-6). The Western part of South Dakota is in the Mountain Time Zone in the United States. Mountain Standard Time (MST) is 7 hours behind Greenwich Mean Time (GMT-7). Like most states in the U.S., Daylight Saving Time is observed in South Dakota, where the time is shifted forward by 1 hour, resulting in a 5 hours and 6 hours difference behind GMT for the Eastern and Western part of South Dakota respectively. After the Summer months the time is shifted back by 1 hour resulting in the normal time difference behind GMT. Daylight Saving Time starts on 3/11/2012 2:00:00 AM local standard time.Daylight Saving Time ends on 11/4/2012 2:00:00 AM local daylight time.