Bill, One of the most basic reasons that Northwest Indiana is in the same Time Zone with Chicago is because so many residents who live in Indiana work in Chicago. This can be accomplished with only a 45 minute commute each way. Could you imagine what it would be like if you (theoretically) had to change your watch every day as you were driving to work and then again when you were driving home??
To add a little more complexity to Time Zone Plan. There are areas on the other side of the planet that have Half-hour Time Zones.
