What is the time zone of South Dakota?

South Dakota is divided into two time zones. The eastern counties and the city of Sioux falls are in the Central Time zone. They are observing daylight savings so there are two different clocks depending on the time of year. 

  • Central Standard Time (CST): – 6:00 UTC/GMT (behind)
  • Central Daylight Time (CDT): – 5:00 UTC/GMT (behind)

Rapid city, the Black Hills National forest and the western part of South Dakota is in the Mountain Time zone and also observing daylight savings so there are two different clocks depending on the time of year. 

  • Mountain Standard Time (MST): – 7:00 UTC/GMT (behind)
  • Mountain Daylight Time (MDT): – 6:00 UTC/GMT (behind)
Mountain Time
Central Time
us state South Dakota counties time zone map
South Dakota time zone
USA time zone map 1
Click to enlarge

All neighbouring states have the same time zone. So, the clocks are unchanged regardless if you cross the border with North Carolina or Georgia.

Zone boundary

The South Dakota boundary between the two time zones roughly follows the Missouri River and Yellowstone river. It borders the eastern side of the counties Corson, Dewey, Jackson, Bennet and the south eastern tip of Haakon. Stanley county is the only county with dual zones.

South Dakota time zone border
South Dakota time zone border

The official border is defined in the Code of Federal Regulations (CFR) §71.7. (b):

Daylight savings time (DST)

South Dakota is using daylight savings as also documented in the Uniform Time Act of 1966. During daylight savings the time changes from Standard time to Daylight time, so CST becomes CDT and MST becomes MDT depending on the location.

It starts on the second Sunday in March and ends on the first Sunday in November. In March the clock is moved forward from 02.00 am to 03.00 am (so you will lose an hour of sleep during the night). While in November it’s reversed as the clock is moved backward from 03.00 am to 02.00 am and you will gain an extra hour of sleep. One way of remembering the movement sequence is that clocks “spring forward and fall back”.

The total period of daylight savings lasts for 34 weeks which is about 65% of the year.

South Dakota time news, bills and legislation

There is a continuous debate about which time should be applied. Several bills have been introduced to legalize daylight saving time as the year-round clock, whereas others try to align the time with bordering counties or states. The table below gives an overview of the latest bills in the state of South Dakota.

Date Bill Status/Action Title/summary
10 Feb 2021 HB1214 Intro, State Affairs Tabled, Passed, YEAS 10, NAYS 3. Provide for permanent daylight savings time when permissible under federal law.
5 Feb 2020 HB1085 House of Representatives Reconsidered, Failed, YEAS 34, NAYS 33. H.J. 168 Provide for permanent daylight savings time.

Other US states

You can check out information and maps of other US states by clicking on the below links.