The Group One Makybe Diva Stakes meeting will switch places with the Dato Tan Chin Nam Stakes fixture as Racing Victoria looks to provide a better flow to Melbourne's spring racing program.

The Makybe Diva Stakes (1600m) was run a week after the Group One Memsie Stakes (1400m) this season but there will now be a two week gap.

The Dato Tan Chin Nam Stakes day at Moonee Valley will be held on September 6 with the Makybe Diva Stakes a week later at Flemington.

Swapping the meetings is also designed to provide an easier transition through the spring towards the Caulfield Guineas for three-year-olds.

Changes have already been made to this year's Caulfield Cup carnival including the Thousand Guineas moving from its traditional Wednesday timeslot to the same day as the Caulfield Guineas, October 11.

The $250,000 Blue Sapphire Stakes (1200m) has been moved to be the feature race on the Wednesday between the Caulfield Guineas meeting and the Caulfield Cup the following Saturday.

Racing Victoria's executive general manager for racing, Greg Carpenter, said with only a week between the Memsie Stakes and Makybe Diva Stakes, it was important to give each Group One race the chance to maximise its potential.

"The swap of dates separates our first two Group One races of the season by two weeks which ensures the races flow into each other and thus have the opportunity to assemble the best fields possible," Carpenter said.

"They are now accessible as legitimate grand final races for the nation's best milers, along with the elite weight-for-age horses heading towards target races over longer distances later in the spring."