About 170 babies will be born in New Zealand on the first day of 2018 and on average they will live long enough to see in a new century, according to new predictions.
Unicef has worked out, in conjunction with the World Data Lab (WDL), that these kids will have some of the longest lives in the world.
Data suggesting New Zealand babies will live until 2100 means they will be able to take in 21 Rugby World Cups, and celebrate the 260th anniversary of the signing of the Treaty of Waitangi.
Babies born in Australia will live a year longer than Kiwi babies on average, and a baby born in Nigeria will have one of the shortest lifespans, predicted to live until approximately 2072 - which is only 55 years.
New Zealand babies will account for just 0.044 per cent of the estimated 385,793 babies to be born globally on New Year's Day.
WDL is the world's most complete data set on human life. Based in Vienna and with hubs all over the world, it's estimates for the number of babies born draws on the period indicators and the life tables of the UN's World Population Prospects. Building on these datasets, World Data Lab's algorithm projects the number of births for each day by country and gender, and their corresponding life expectancy.
Unicef challenges nations around the world to make sure more newborns survive their first days of life, Unicef NZ executive director Vivien Maidaborn said.
"Babies born in New Zealand have access to high levels of care, education and medical assistance, which is reflected in their long lifespans.
"Our hope is that by the time these babies reach adulthood, the success we see in New Zealand is shared with other countries around the world.
"This New Year, Unicef's resolution is to help give every child more than an hour, more than a day, more than a month - more than survival. We want to see governments and partners join the fight to save millions of children's lives by providing proven, low-cost solutions."
Over the past two decades, the world has seen unprecedented progress in child survival, halving the number of children worldwide who die before their fifth birthday to 5.6 million in 2016, Maidaborn said.
But despite these advances, progress has been slower for newborns. Babies dying in the first month account for 46 per cent of all deaths among children under 5.
"We are now entering the era when all the world's newborns should have the opportunity to see the 22nd century.
"We want to see all babies living the same long and happy lives as babies born in New Zealand and other developed countries."
One of New Zealand's leading heath researchers, Professor Peter Shepherd, said life expectancy in developed nations had been slowly trending toward 100 for some time.
A new generation of treatments for cancer, long our biggest killer, could have the potential to delay deaths by 15 to 20 years, while great strides were also being made against a range of neuro-degenerative diseases.
"These are the things that we are really getting on top of, and the curve of age and survival are going up across the board," said Shepherd, deputy director of the University of Auckland-based Maurice Wilkins Centre.
"The only one that is still a problem in terms of life expectancy, and which remains a major killer, will be diabetes and the related illnesses that come with that."
Despite hype around potential scientific interventions touted to physically "stretch" life expectancy, Shepherd said there not yet any miracle pill that could add years to life.
"The best evidence we have is perhaps for nutrient restriction - people eating a very low calorie diet - but these are very hard things to stick to for your whole life."
Shepherd acknowledged that developing nations were still struggling with healthcare - but pointed out inequalities in New Zealand's own health profile.
"If we look to our own situation, the life expectancy for Maori and Pacific Island people is still a lot lower than for Europeans, and I think we should be putting a lot of focus on understanding the reasons for that.
"Part of it will be genetic, but much of it will be preventable and range from things like rheumatic fever to diabetes."
Kiribati's Christmas Island, a small island in the Pacific will most likely welcome 2018's first baby; the United States, its last.
(Kiribati's Christmas Island is a different island to the Christmas Island in the Indian Ocean, an Australian territory).
Globally, more than half of the almost 400,000 births are estimated to be in nine countries:
• India — 69,070
• China — 44,760
• Nigeria — 20,210
• Pakistan — 14,910
• Indonesia — 13,370
• United States — 11,280
• Democratic Republic of Congo — 9400
• Ethiopia — 9020
• Bangladesh — 8370