Tennessee Code Title 40. Criminal Procedure § 40-17-108

(a) It is the duty of the clerks of the circuit and criminal courts to designate on the dockets of their several courts the days on which the criminal cases in those courts will be called for trial, subject to the direction and control of the judges of those courts, and subpoenas for witnesses shall require their attendance only upon the day designated for the trial of the particular case in which they are summoned.

(b) It is the duty of the clerks of the circuit or criminal court to subpoena witnesses in causes set for trial, to appear on the day fixed for trial, at the first term that the causes are placed upon the docket. It shall not be necessary to resubpoena the witnesses to subsequent terms, but they shall be required to attend at subsequent terms, upon the day fixed for the trial of the causes, and from day to day of the terms as required by the court, until the causes are disposed of.

(c) It is the duty of the district attorney general and the clerk, in summoning witnesses in state cases, to specify the day on which they are required to attend, and to use all proper precautions to diminish the cost as much as possible.

(d) If for any reason the case or cases so set for trial shall not be tried on the day fixed, it is the duty of the court, by special order, to designate some other day on which the case will be tried; and, in the absence of a special order, it shall not be necessary for witnesses to attend the court, and if they shall attend without a special order, it shall be at their own option. It is the duty of the district attorney general and the clerk to ensure that every reasonable effort has been made to notify witnesses of any change in the date set for trial. Notice shall be given at least ten (10) days in advance of the new date set for trial.