Epsom has switched the start of the Betfred Derby to 1.30pm on June 3 to avoid a clash with the FA Cup final.
The 244th running of the most important Classic of the Flat season had been scheduled for 4.30pm but it will now be the second race on the card.
Mail Sport revealed earlier this week that changes would be needed after the Metropolitan Police deemed the FA Cup final between Manchester City and Manchester United to be high-risk.
Consequently, the kick-off was moved from 4.30pm to 3pm.