I can NOT remember when the switch occurred, sometimes in the 1970s if I remember right. I remember looking at a phone book in the late 1960s, early 1970s and it had a map of the time zones in it, with Michigan cut in half. Detroit in the Eastern Time Zone, the Western half of the state in the Central Time zone. I tired to find some confirmation of this but all I could find was the following cite that states Indiana and Kentucky made a switch in 1961 between the two time zones.
According to this site, Eastern Indiana and Central Kentucky were moved from the Central Time Zone to the Eastern Time Zone in 1961:
http://www.statoids.com/tus.html The following has a short comment on Detroit and time zone:s
http://www.exactspent.com/time_zone.htm The Comment is "A notable exception was Detroit, Michigan, which kept local time until 1900, then vacillated between Central Standard Time, local mean time, and Eastern Standard Time until it settled on EST by ordinance during May 1915, which was ratified by popular vote during August 1916."
They would be no problem if the Time zones were only one hour wide, but fro various reasons the Eastern Time Zone was made larger then One hour by the Railroads in 1883 and has expanded since that date. Thus you have areas of the Country in the Wrong Time Zone for the people in power want to be able to contact people in New York City and Washington DC and NOT have to worry about the time.
A good example of this is Michigan for its should be in the Central Time Zone (i.e. with Chicago) but to many people want to be able to call and get in contact with people in New York City and Washington DC, thus it stays with Eastern Time, instead of Central Time.
I think 5:00 pm sunset is to early, 4:00 would be WAY to early given both Michigan and Pennsylvania are seeing 10 hours of daylight in November. i.e daylight is from 7:00 am till 5:00 pm in Johnstown today, but in Michigan it would be 6:00 am till 4:00 pm., when the normal expected work day is 8:00 am till 5:00 pm. It makes leaving work to much like the old line about leaving the coal mines, you entered the mine when it was dark, left it when it was dark, and worked in the mine in the dark. Sorry, Michigan, Indiana and the Western Half of Tennessee and Kentucky should be in the Central Time Zone (and I can make the argument ALL of Tennessee and Kentucky and Ohio, should be in the Central Time Zone). 4:00 is to early for sunset at the Latitudes these states are located at (Alaska and Northern Canada is a different story, being so far north and even less hours of daylight).