Matthew's trial in Fairfax County was initially scheduled to begin March 9, but a judge postponed the trial earlier this month. Matthew's lawyers had said they needed more time to prepare for trial.
Matthew's new trial date was set Friday in a case dating back to 2005.
He is accused of attempted murder and sexual assault of a 26-year-old woman who was attacked while walking home from a grocery store. The woman was dragged into a wooded area; her assailant fled after being startled by a passer-by.
Matthew has pleaded not guilty.
He was charged last October, a few weeks after he was arrested in the Graham case.
Matthew is also charged with the murder of Graham, who went missing in September after a night out with friends. Her body was found a month later.
Before the identification of Matthew as a suspect, authorities said they had linked the 2005 Fairfax case to the 2009 disappearance of Virginia Tech student Morgan Harrington, who vanished after attending a concert at U.Va. Her remains were found in early 2010.
Matthew has not been charged in the Harrington case.
Matthew's Fairfax trial is expected to last about two weeks.