The Adelaide carnival has been moved by a week to avoid a clash of Group One racing with Brisbane and will now run over three Saturdays in May.

South Australian authorities decided to begin their feature racing a week later alterations to the dates of the Brisbane winter carnival.

Adelaide's carnival will now begin on May 2 with the Group One Schweppes Oaks and the Robert Sangster Stakes.

The South Australian Derby will be on May 9 with Adelaide's feature sprint, the Goodwood, the following Saturday.

Thoroughbred Racing SA chief executive Watters said when Queensland racing authorities proposed date changes to their carnival, it opened the door for changes in Adelaide.

"We identified two opportunities where South Australian racing would provide the feature racing nationally each day, on May 2 and May 16, if we moved our carnival by one week," Watters said.

"By making this change, we avoid the Goodwood and Queensland's BTC Cup, both of which are Group One 1200 metre events with $500,000 in prize money, being run on the same day.

"The revised dates mean South Australian racing is showcased across Australia and leading interstate riders and trainers are more likely to compete in Adelaide on each day."