The census is a government survey run every five years by Stats NZ.
It gathers a "snapshot" of New Zealand, which helps to inform future decisions about funding, infrastructure and electoral boundaries.
Everyone in the country tonight is legally required to complete the questionnaire, which can be done on paper or online.
Otago Yacht Club manager Jeff Lyell, of Dunedin, said all the questions were relatively straightforward and he would be completing them to the best of his knowledge.
Filling out the census helped the country plan for the future and was part of his civic duty, Mr Lyell said.
While some of the questions, such as the section on gender, had changed a little from previous years there were no real surprises.
He had recently moved to the club’s Magnet St premises, where he was tracked down by a census worker.
Finding him showed the systems in place were working to a degree, and he hoped this year’s census would be be better than the 2018 census, which was marred by low completion rates after a digital-first approach was tried.
Two people were scheduled to arrive at the yacht club yesterday evening and as it was likely they would also stay tonight, they would be obliged to complete the census.
While it was unclear how best to account for mobile homes and boats, Mr Lyell had some spare forms and would be doing the best to make sure the new arrivals got to complete them, he said.
Otago University senior lecturer in statistics Dr Peter Dillingham said the goal of a census was to get a snapshot measurement of a population at a given point in time.
The data was used for official statistics and a range of government decisions, including funding decisions, infrastructure needs, changes in population demographics and electoral districts.
"It’s a hugely important undertaking," Dr Dillingham said.
The data was controlled in a very strict way, with strong protections for privacy and requirements to use it in an anonymised and aggregated way.
Compared to commercial companies which harvested user data, the government had stricter guidelines and cared more about privacy and data security.
"Commercial companies get hacked all the time ... that’s not something I’m worried about with government data. They have much stricter protocols," Dr Dillingham said.
