The final three days live racing for the Churchill Downs spring meet will be held Friday through Sunday, but under a revised schedule.High temperatures around the 100 degree mark forced Churchill Downs to cancel its Thursday racing card. Spokesman Darren Rogers says it was just the 18th time in the track’s long history that the races were called off."All of those (were) weather-related in some fashion, but that is the first time we’ve ever had to cancel due to extreme heat," he said.The heat wave will continue for several days, and that has prompted Churchill Downs to delay post times Friday through Sunday, the final three days of the spring meet.Races will begin at 6:30 each evening. Night racing was already scheduled to begin at 6:00 Saturday. Officials say the delay will allow racing fans and horses to avoid the hottest part of the day. "Horses are a lot like humans, where you give them extra electrolytes and keep them hydrated," Rogers said. "We hope to keep the fans hydrated as well. (We) plan to have a lot of water around the facility."