The “one day/one trial” system has been in effect since 1990 and describes the length of service required for trial jurors. Grand jurors serve a term of twelve months. “One day/one trial” means that any person who is summoned and appears for service may be released from further service unless that person is assigned to a particular trial. When a juror is assigned to a trial, the length of jury service will be for the duration of that trial. In Colorado, the average length of a trial is three days.