New Zealand's High Court on Thursday postponed the start of the trial for the Australian man accused of murdering 51 Muslim worshippers at Christchurch mosques to avoid the hearings clashing with Ramadan.
Australian Brenton Tarrant's trial was scheduled to begin on May 4, 2020, which falls during the Islamic holy month next year.
A statement released by the court said prosecutors were concerned the clash would pose a problem.
"A number of the witnesses to be called at trial are of the Islamic faith," it said.
It said a new June 2 start date for the trial had been confirmed after the defence raised no objection to the change.
The court is scheduled to hold a brief hearing on October 3, when it is expected to make a decision on a request by the defence team to move the trial away from Christchurch.
The South Island city was the scene of the worst mass shooting in modern New Zealand history on March 15, when a lone gunman opened fire at two mosques while livestreaming his actions on social media.
Tarrant, a self-avowed white supremacist, has been charged with 51 counts of murder, 40 of attempted murder and engaging in a terrorist act.