Time in Michigan
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 05:50:27 west of Greenwich.
Time zones were introduced in the United States in 1883. They were introduced in different years based on local decisions. Michigan adopted Central Standard Time throughout the state effective September 18, 1885. In 1915, Detroit changed to Eastern time, followed by most of the rest of the state in 1931.
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.
IANA time zone database
|c.c.||coordinates||TZ||comments||UTC offset||UTC offset DST||Note|
|US||+421953−0830245||America/Detroit||Eastern - MI (most areas)||−05:00||−04:00|
|US||+450628−0873651||America/Menominee||Central - MI (Wisconsin border)||−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|
- "MICHIGAN'S EARLY TIME". The New York Times. 1885-09-19. ISSN 0362-4331. Retrieved 2021-02-24.
... among the laws now in force are the 10-hour labor law and an enactment making central standard time legal in this State.
- "Standard Time Adopted". The Detroit Free Press. 1885-09-12. Retrieved 2021-02-24.
- "STANDARD TIME". The Detroit Free Press. 1885-09-18. Retrieved 2021-02-24.
Standard time becomes legal in Michigan this morning.
- "Why is Michigan on Eastern Time? Thank (or blame) Detroit". The Night Train. 2017-07-28. Retrieved 2021-02-24.
- "State Constitutions: Referendum Row". Time. July 7, 1967. Archived from the original on August 11, 2016. Retrieved February 24, 2021.
- Law, Gwillim (February 19, 2007). "United States Time Zones". Statoids. Retrieved July 25, 2007.