Miami-Dade County Chairman Dennis Moss said the county won’t vote on a proposed new stadium for the Florida Marlins until March 9, four days later than originally scheduled. The $609 million project would be a centerpiece of development in Little Havana. Not all county commissioners would be able to attend the earlier vote. Two commissioners are threatening to vote against allowing the Marlins’ chosen construction firm to make infrastructure improvements around the stadium without a formal bidding process. The city has also delayed its stadium vote, which was supposed to take place last week.