"I'm just thrilled that we're able to turn it around so quick and we're able to hit New Zealand so soon. Going up against Pearl Jam - hey, it is what it is and we'll have a blast regardless," he tells TimeOut.
"This was to be our designated time off after a little over a year of touring. But we have no complaints at all - it's summertime, and we're playing, as they call it, the Big Day Off."
Deftones, along with The Hives and Beady Eye, were called in as last-minute replacements when Blur pulled out in November. They've played the Big Day Out twice before: an unhinged but wayward mid-afternoon set in 2003, and a much improved early evening showing in 2011.
But tomorrow's show promises to be different. The 9pm timeslot means frontman Chino Moreno and the boys will be playing the Big Day Out in the dark for the first time - the perfect setting for their moody and unsettling brand of prog-metal riffage.
"We're one of those bands that can pretty much play any time of day and it'll be a good time, but night-time lends itself to lights and moods," Cunningham says.
"We're a band that relies on music and smiles and interaction between each other. We'll have a nice light package and kickass sound system. We'll cram in a set of bangers and just bang it out on into the night."
For fans concerned the festival appearance might delay sessions for their next album, Cunningham says they still plan on recording the follow-up to 2012's excellent Koi No Yokan later this year.
He admits that, despite some well-publicised tensions that almost saw the band split after recording 2003's brutally heavy self-titled record, life "is good "for the five-piece these days.
"We've been around for 25 years now, which is pretty crazy. We're in a good spot, we're all on the same page, enjoying what we do and enjoying the fact that we're still able to do it and people are showing an interest.
"We're really focused on maximising now. We're loving each other. We're brothers, there's always some bickering and some fighting - that's life in a band."
But Cunningham admits their newfound appreciation stems from what he calls "a really f*****-up time".
He's talking about the death of the band's bassist, Chi Cheng, in April last yea. He had been in and out of a coma since a serious car accident in 2008.
The band were halfway through recording the album Eros when Cheng had his accident - a record that was put on hold and replaced by 2010's return-to-form Diamond Eyes, with Sergio Vega stepping in for Cheng.
But Eros has reached mythical status among Deftones fans, and demands to hear it have escalated since Cheng's death.
Cunningham says Eros will be released one day, but claims it's too soon to go back and finish the album.
"People are interested and that's a beautiful thing, but the fact is it's never been completed. I have it, it's pretty cool, but it's not done. It's not sitting in a can ready to go. It'll take some work.
"A lot of that was written with Chi, and it's an emotional album for many reasons. I know people deserve to hear it, and should hear it but it's not so easy to go back to that. To go back to that, it's not just something you want to jump into. That's not to say we won't and it's no disrespect to him at all, but that was a terrible time.
"From that point on we went forward and never looked back."
Who: Deftones
Where: Big Day Out 2014
When: Friday, January 17, 9pm, Tamaki stage 1
Essential listening: Around the Fur (1997), White Pony (2000), Deftones (2003), Koi No Yokan (2012)
- TimeOut
