Phuket Criminal Court set March 18-20 as the trial date for Australian Alan Morison, editor of news website PhuketWan, and his Thai reporter Chutima Sidahathien, Morison said by phone.
"It's pretty unusual for a judge to schedule a trial that far ahead," he said.
The pair were indicted on April 17 for putting online parts of a Thomson Reuters article on the trafficking of members of the Muslim ethnic Rohingya group in southern Thailand and Myanmar.
They face charges of criminal defamation and violating the Computer Crime Act, and possible imprisonment if found guilty.
It is the first time the Thai military has used the Act, designed to prosecute hackers and other IT offences, in a defamation case.
The journalists' first day in court Monday in Phuket, 750 kilometres south of Bangkok, follows Thursday's coup by the military.
The coup makers have put in place strict controls on the media.
"So far the coup has been bad for our case in that we had planned a mediation meeting with the navy at the National Human Rights Commission on Friday, but after the coup the navy had a good excuse not to show up," Morison said.
The defendants maintain that the Thai Navy was not named as a participant in the alleged trafficking.
Thomson Reuters journalists Jason Szep and Andrew Marshall last month won the Pulitzer Prize for investigative reporting for the article, which was reprinted on the PhuketWan site in July.