The first, Tyrell Fraser, was born at Dunedin Hospital at 12.16am yesterday - 11 days later than expected - weighing in at a healthy 4.05kg.
Proud mother Aroha Condon (30) said she had been ''trying my best'' to make it to midnight to deliver New Zealand's first baby for 2013.
She was not sure if she had been pipped by other new arrivals around the country yesterday, but thought her son would appreciate her efforts anyway.
''It will be cool for him when he gets older,'' she said.
Her partner, Brett Fraser (29), said the new arrival meant New Year's Eve was ''one I will remember''.
The couple - who are engaged - spent yesterday introducing Tyrell to his big sister, Atiya (9), and brother Tremaine (2), and hoped to go home later in the day.
Tyrell was one of five babies born at Dunedin Hospital on New Year's Day. He was followed by a girl at 3.48am, another boy at 5.07am, a girl at 7.01am and a boy at 9.59am, duty co-ordinator Trish Walton said.
She could not explain the sudden rush, saying so many New Year's Day babies was ''unusual''.
''Usually we don't have that many,'' she said.
Dunedin was not alone, however, with three babies arriving in a rush on New Year's Day at Southland Hospital in Invercargill - two girls, at 4.07am and 6.37am respectively, and a boy at 12.49pm, staff said.
Queenstown's Lakes District Hospital, Balclutha's Clutha Health First and Oamaru Hospital all missed out on New Year's Day babies.
Staff at Alexandra's private provider, the Charlotte Jean Maternity Hospital, reported the arrival of one baby, but said they could not disclose details.
However, independent midwife Vicki McMillan, of Alexandra, said she delivered a baby girl in a home birth in Cromwell at 4.40am yesterday.