IMSA O’Reilly Auto Parts 4 Hours of Mid Ohio debuts June 03- 07, 2026 to Mid-Ohio Sports Car Course. Hours: Wednesday, 6/03: 8 AM – 5 PM Thursday, 6/04: 8 AM – 5 PM Friday, 6/05: 8 AM – 6 PM Saturday, 6/06: 8 AM – 6 PM Sunday, 6/07: 8 AM – 1 hour after races conclude.