After the hearing, relatives and survivors were left baffled outside the courtroom, where they had expected to hear arguments about the proposed change in venue, as court staff members explained the proceedings to them.

In the months after Mr. Tarrant’s arrest, New Zealand’s court system was criticized by some of the victims’ families and their advocates because initial hearings were scheduled for Fridays, the sacred day for Muslims and the day of the week that the attack took place. The hearings were switched to Thursdays in recent months, after families complained.

The Justice Ministry earlier said it had introduced new cultural and language services at the court house, including a prayer room, in response to feedback from the community.

The judge, Cameron Mander, has also adjusted the potential trial date. The trial was initially set for May 2020, during Ramadan, the holy month of prayer and fasting for Muslims, and officials appeared not to have realized the conflict. The trial, which is expected to run at least six weeks, is now scheduled to begin on June 2.

The scale of the Christchurch case is unprecedented in a country that has never tried a mass shooting of anywhere near this size, and it is expected to challenge the court system.

Seating for court hearings will be in high demand, with dozens of survivors and victims’ relatives, and a large international news media contingent. Security risks will also confront the court; at a June hearing in Mr. Tarrant’s case, a man was charged after he played pro-Nazi music outside the court and confronted a survivor of the attacks.

Mr. Tarrant’s guards at the prison in Auckland where he is being held, the country’s only maximum security facility, were embarrassed in August when they were forced to admit that he had sent letters to supporters from his cell. At least one, which was posted on the message board 4chan, contained a call for racist violence.