Ten years on, we snigger about those Y2K doomsday predictions that came to nothing at midnight 2000. But those who worked to counteract the millennium bug say the billions spent helped to prepare the world for events to come.
On New Year's Eve 10 years ago, Ted Christiansen was sitting in the Beehive bunker in Wellington, nervously waiting for the end of the millennium.
Elsewhere in the world, others were waiting for the end of life as they knew it - fuelled by predictions from doomsday prophets that when the clock struck midnight at 2000, all hell would break lose. The theory was that millions of microchips installed in everything from aircraft to the electricity grid would be unable to cope with the date and would either cause a shut-down or throw up the wrong data.
Christiansen didn't think so, but he, and thousands of others working to protect the world from Y2K, could not be sure.
As Y2K project manager for the State Services Commission, Christiansen led the team that had to ensure government agencies, ranging from the Defence Force to Social Welfare, took the millennium bug seriously.
As December 31, 1999, ticked by most of New Zealand got ready for a once-in-lifetime celebration - the new millennium. There were fireworks to watch, parties to go to, the new century's dawn to witness early on the morning of January 1, 2000.
The doomsday stories had been making headlines five years earlier. "Computer doomsday looms" read a headline in the New Zealand Herald in 1996. While some brushed it off as a ploy by the likes of Microsoft to earn big bucks by stirring up panic in a western world run by computers and microchips, American survivalists made plans to escape to the wilderness.
Throughout the world, Y2K task forces were set up to second-guess how computerised systems controlled by microchips might behave and to devise back-ups.
During 1999, New Zealand householders were urged to stock up on the Y2K Readiness Commission's B-Ready checklist - much like the Civil Defence list promoted today. The commission posted out fridge magnets to remind people to buy bottled water and canned food, have their battery radio ready, and to fill their gas canisters and stock up on toilet paper.
Christiansen remembers the biggest problem was convincing government agencies and the public that the Y2K bug threat was real. "Afterwards people said it was a beat-up because nothing went wrong."
But things did go wrong, he says. "Nobody died" but there were bugs. For example a South Island hospital discovered faults in the automatic drips releasing drugs into patients' veins. "One of them worked fine, one of them stopped because it couldn't figure out what was happening and one of them thought the day was wrong so it doubled the dose."
Christiansen had seen what could go wrong four years earlier when the Tiwai Pt aluminium smelter in Southland shut down, unable to cope with the Leap Year's February 29. Hundreds of computers that run the smelter's potlines hung, their chips confused by the date. Two hours later in Tasmania, Comalco's Bell Bay smelter, run by the same software, shut down. The Tiwai shut-down cost New Zealand Aluminium Smelters more than $1 million.
Christiansen's team had a top-level mandate to make sure nothing like that happened in 2000. "We could go into government agencies and say 'I don't care if you believe us or not but you will do the following things.' We had to get a little direct with some of them."
Worst-case scenario was the electricity and water would shut down, air traffic control systems would stop, hospital power supplies would fail, chaos and panic would ensue.
The worst problem, Christiansen says, was not knowing. Would computerised systems stop or keep going but give incorrect, and potentially dangerous, readings? Would the back-ups work? Had the computer engineers thought of everything?
"We did some quite significant practising for disasters," he says.
What would happen, the task force asked, if the government computer system shut down and no benefits could be paid? "If you can't pay them ... you are about three days away from food riots."
If the back-up systems failed, there was another plan - armoured cars loaded with cash to distribute money around the country. The Reserve Bank had "large stockpiles of folding stuff put aside", Christiansen says.
He says it would have been a good time to rob the bank. "How would you tell whether it was a bank systems failure or a robbery? A lot of this stuff was thought about."
All police leave was cancelled and the Army was on standby. Police were issued radio frequency transmitters which did not use microchips.
As midnight approached at the Beehive, Christiansen's daughter, who was with him, spotted fireworks going off. Why not turn out the lights so they could see them better, she suggested.
"We looked at each other and thought 'No, that would be entirely the wrong message."'
The bunker, he says, was "an awful place to spend the end of the Millennium". "At that point there really was nothing to do other than cross your fingers and wait, and hope like hell we'd got it right."
As midnight in New Zealand approached, other parts of the world were watching. If the Y2K bug played havoc here, others countries would at least have a few hours' warning.
But, it appears, they did get it right. Critics say Y2K was a multi-billion-dollar to-do about nothing. Not so, say Christiansen and others like him. The back-up systems developed for Y2K have been useful for pandemic planning, the Sars virus and swine flu and will continue to be useful for "other potentially catastrophic events".
Take the IRD's coded mathematical digits used to identify every taxpayer, he says. Eventually the number formations, which can never be repeated, will run out and the IRD will need to add another digit.
"Which means every payroll system in the country has to change, every banking system has to change."
It's not quite like the electricity and water shutting down but if handled incorrectly it could cause chaos. "We will know so much better about how to deal with that."
IT specialist Robert Nippert also thinks the big spend leading up to Y2K was crucial. Nippert was global project manager for the Dairy Board in the two years leading up to 2000 and spent three months visiting 24 subsidiaries in 17 countries to identify potential Y2K problems and check robust back-up systems were in place. The board spent more than $1 million to Y2k proof itself and by the time New Year's Eve dawned, Nippert was sure nothing more could be done. To show his confidence, he spent New Year's Eve with his family at Lake Taupo while other executives waited anxiously at the board's headquarters in Wellington.
Ten years later Nippert admits he was nervous as midnight struck. "I didn't look at the fireworks, I was watching the lights... to see if they stayed on."
The resulting Y2K problems were "relatively trivial" and he can still reel them off: The Dairy Research Corporation PABX at Palmerston North came up with the wrong time but the phone still rang; in Singapore some computer servers had the wrong date "but a reboot fixed that" and at Anchor Foods in Swindon, England, one of the label machines had the wrong date.
The $1m was well spent, he says. "If we had done nothing we would have had real problems."
Ten years ago this New Year's Eve, Gavin Ellis - then editor of the New Zealand Herald - was sweating as midnight loomed. Because of the time zone, other newspaper owners around the world were watching and waiting with Ellis.
"We were the first paper in the world to go through the vortex. I was sweating blood up until the clock ticked over because none of us really knew for sure. We had spent a lot of money and a lot of time ... to upgrade the systems but there was still no absolute guarantee that the power supply, for example, would still be there."
Just after midnight the paper received "an avalanche" of anxious calls from other media organisations around the world wanting to know if the Herald's editorial computer systems were still working.
"Nothing went wrong, at all, says Ellis. "It was an extraordinary anti-climax. It was just another day."