Eastern Time (EST/EDT) · Indianapolis · NW Indiana on Central Time
Indiana has the most complicated timezone history in the US. Until 2006, most of Indiana did NOT observe DST — making it one of only two US states (with Arizona) to skip it. This meant Indiana's time relationship with neighboring states changed twice a year, causing massive confusion.
Indiana has 5 separate IANA timezone entries: America/Indiana/Indianapolis, America/Indiana/Knox, America/Indiana/Marengo, America/Indiana/Petersburg, and America/Indiana/Vevay. This is because different counties switched between ET and CT — and adopted or rejected DST — at different times throughout history.
The Indy 500 (the world's largest single-day sporting event, 300,000+ attendees) starts at 12:45 PM ET on Memorial Day weekend. The race has been held annually since 1911 — making it older than most timezone standardizations.