The scientific knowledge about the cult in Didyma is not much. All we know is the information obtained from a marble stele which was written in the 2nd century B.C. found in Delphi of Miletus. According to the writings, they used to make one major ceremonial worship once a year in spring.
As the rites in Apollo Delphi was over, they were leaving Miletus through the Holy Gate and setting up to the Sacred Road, to Didyma. This ceremonial walk used to take 4 days before they reach to the temple of Apollon in Didyma. They would offer sacrifices to Apollon in front of the sacred quarters. After a final holy ceremony in the Apollon temple the annual worship would end. The whole ceremony was conducted under the leadership of a family of priests.
During the time of Theodasius (395 A.C.), oracling was forbidden in the temple of Apollon.