Thomas William Gray was born two minutes into the new year - more than two weeks overdue and after an emergency procedure.
His father, Clint Gray, of Pukekohe, said Thomas seemed determined to wait until 2012 to come out.
The newborn's names rank among the most popular for the past year: Thomas was 19th and William 5th in 2011.
Mr Gray said Thomas was meant to be an Oliver - the number three name.
But two days after his birth the couple came up with Thomas William Gray as a name that seemed appropriate "for someone who is going to make his mark for good in this challenging world".