From the web:
76 counties (including state capital Indianapolis) are in the Eastern Time Zone but do not change to Daylight time in April; instead they remain on Standard Time all year long;
11 counties -- six near Chicago, IL, and five near Evansville, IN, are in the Central Time Zone and use both Central Standard and Central Daylight;
5 other counties -- two near Cincinnati, OH, and three near Louisville, KY -- are in the Eastern Time Zone but use both Eastern Standard and Eastern Daylight.