The Heaphy Track is one of the Great Walks. Photo: Crown Copyright DOC
The Department of Conservation has apologised for delays to Great Walk bookings, saying they will reopen in mid-June.
On Wednesday, DOC chose to postpone bookings for most Great Walks after discovering a technology glitch.
A week before, 10,000 people attempted to book the Milford Track with a separate glitch causing the system to crash for several hours.
Heritage and visitors director Cat Wilson said its IT vendor had identified a new and specific fault linked to an availability search function.
The department had asked the vendor to review every change they made to the system since last season while working to fix the issue, she said.
"We are very sorry for the frustrations people have met with when using our booking system recently, and the delay of Great Walk openings until mid-June.
"We understand how much our incredible Great Walks network means to people, and how keen they are to book their spots. We are very disappointed with the issues experienced with our booking system and we're working closely with our IT vendor to fix it."
On Wednesday, DOC said new dates would be posted on its website and via social media this week.
The department has now confirmed the new booking dates will be announced on 31 May.
"We need to take this time to gain complete reassurance from our vendor that all issues are resolved."
Current bookings for Great Walks, huts and campsites this season remain unaffected.