The history of Indiana with daylight saving time Famously, Indiana is divided into two time zones. Most of the state is in the Eastern Time Zone, but several counties near Gary and Evansville remain in the central time zone. Indiana enacted the statute, officially placing northwest and southwest Indiana in the central time zone, in observance of daylight saving time, and the rest of the state in Eastern Standard Time throughout the year. Supporters of daylight saving time and a common time zone in Indiana often assert that Indiana must adopt the Eastern United States timing system to preserve interstate business with that region.
Daylight saving time detractors say that scientific studies evaluating the impact of the shift in hourly policy to daylight saving time in Indiana have identified a significant increase in energy use and electricity spending by Indiana households. Several counties in eastern Indiana (Ohio and Dearborn Counties, near Cincinnati; and Floyd, Clark and Harrison Counties, near Louisville) chose to unofficially observe daylight saving time, despite Indiana law. But in 1985, the Indiana General Assembly, in Senate Concurrent Resolution 6 of 1985, called on the USDOT to move five southwestern Indiana counties (Posey, Vanderburgh, Warrick, Spencer and Gibson) from the central time zone to the eastern time zone. Debate in the city, the Indiana General Assembly passed a law to place all of Indiana on central standard time and ban daylight saving time.