Whatâs the schedule? The first Democratic primary debate is split over two nights â the first taking place on Wednesday, June 26 and then Thursday, June 27.The debates kick off at 9 p.m. E.T. in Miami, Florida.A total of 20 candidates â 10 each night â will debate. Candidates were randomly selected to appear on the first or second night.Whoâs debating when? On June 26, the following candidates will debate:New Jersey Sen.