Parents taking their children on holiday during term time are a rising trend, according to one Hawke's Bay principal.
Hawke's Bay's school absence rate was 11.3 per cent last year, up on the previous year's 9.8 per cent, according to the Ministry of Education's Attendance in New Zealand Schools 2014 publication.
The attendance survey is a snapshot of school attendance data from one week in term two of last year.
Hawke's Bay's unjustified absence rate was 4.7 per cent last year, up on the previous year's 3.3 per cent.
Its frequent truant rate, which measures students unjustifiably absent for three or more days in the survey week, rose to 1.3 per cent from 1 per cent.
Napier Boys' High School principal Ross Brown said the school hadn't noticed a significant lift in absences. He said most absences were driven by illness.
"In terms of truancy, I think it's more illness driven than a behavioural choice."
He said the high school had unjustified absences, like any school, but it wasn't a major reason for students to be away.
Parents taking students on holiday during term time to take advantage of cheap rates was another rising trend, he said. He'd had conversations with parents about the issue from time to time.
"The annoying thing is parents want to take their kids out but they want them to take work as well. Well, the easiest solution is leave them in the school."
He said the school didn't own the students but they were required by law to be in school.
The national absence rate increased slightly last year on the previous one. The proportion of justified absences remained unchanged, so the increase in the national rate was due to an increase in unjustified absences, according to the ministry publication.
The total unjustified absence rate was 4.6 per cent compared to 3.9 per cent in 2013.
The national frequent truant rate was 1.3 per cent compared to 1 per cent in 2013.
Frequent truancy was highest for students in Year 13 and for Maori students, according to the publication.
New Zealand Principals' Federation national president Denise Torrey said a large amount of illness had been around this year.
"Unfortunately with so many working parents we find many children still turn up to school sick and therefore infect others."
Parents had financial pressures and it was difficult for those who didn't live near extended family to find support for children when they were sick, she said.
That made things difficult for schools as they didn't have facilities to look after sick children.
Children going on holiday during term time was definitely a rising trend and the ways schools viewed those absences varied, said Ms Torrey.
Parents were working in a greater variety of jobs and not everyone could take Christmas and school holidays off.
"It's a balance between family time or not, for many," she said.