The ability to change court dates depends on the rules of the jurisdiction that the court is held in. Many times, a court date can be changed if one of the lawyers is unavailable or if there is some type of pending emergency with someone involved in the case.
While the rules vary from court to court, it's possible to get a court date postponed or moved once or twice, but there needs to be a good reason for doing so. One of the parties may need more time to prepare a witness or gather additional information. In addition, a party in the case may become ill, or one of the attorneys may have a scheduling conflict. The best way to obtain a change in a court date is to write or call the court.