Time in Michigan
Almost all counties in Michigan's Lower Peninsula observe Eastern Time, as do most counties in the state's Upper Peninsula. The U.P. counties that do not, the four counties which have a land border with Wisconsin, are in the Central Time zone.
Before time zones were introduced, every place used local observation of the sun to set their clocks, which means they used local mean time, every city different based on their longitude. Detroit used 05:32:11 west of Greenwich and Menominee 05:51:31 west of Greenwich.
Time zones were introduced in the United States in 1883. This was in introduced in different years based on local decisions. Detroit introduced Central time on January 1, 1905. and Menominee on 18 September 18, 1885. In 1942, Detroit and most of Michigan changed to Eastern time.
In 1967, when the Uniform Time Act came into effect, the Upper Peninsula went under year-round CST, with no daylight saving time. In 1973, the majority of the peninsula switched to Eastern Time; only the four western counties of Gogebic, Iron, Dickinson, and Menominee continue to observe Central Time. There are only two cities in the Lower Peninsula of Michigan part of Berrien County that observe Central Standard Time, Michiana and Grand Beach, both of which are in southwestern Michigan bordering the part of Indiana that uses Central Standard Time.
IANA time zone database
|c.c.||coordinates||TZ||comments||UTC offset||UTC offset DST||Note|
|US||+421953-0830245||America/Detroit||Eastern Time - Michigan - most locations||−05:00||−04:00|
|US||+450628-0873651||America/Menominee||Central Time - Michigan - Dickinson, Gogebic, Iron & Menominee Counties||−06:00||−05:00||Was used statewide from January 1, 1905 until May 15, 1915. This was prior to the advent of DST, so UTC-6 was used all year long|