The summer school holidays would be shortened by up to two weeks under a proposal by a National Party list MP.
Nicola Willis, who argues the case for a shorter break in an opinion piece in today's Herald, said she intends to write a private member's bill to implement the idea.
These bills are debated in Parliament only if selected in the random ballot.
"I think it's time to talk about whether a six-week holiday makes sense in 2019," Willis says in her article.
"Should the summer break be shortened to five or even four weeks?"
Most state and integrated schools open between today and February 7, for a 2019 academic year of up to 41 weeks.
Willis said the reality was that most parents worked, had four weeks' annual leave and obtaining childcare during holidays could pose problems.
"The modern family is juggling childcare and work and the school holidays turn the pressure and costs up a notch."
"Making the summer break just one week shorter could really help."
Most important, Willis said, was that the long summer holiday could harm children's academic achievement.
"Kids' literacy abilities can decline over the six-week break, with one study showing students lowing months of progress over summer. Much of term one can be spent getting kids back to where they left off the following year."
Willis said teachers worked hard and deserved good holidays. They also needed non-contact time for preparation.
"At the moment, teachers can be required by school boards to attend school for up to 10 days during the 12 weeks of school holidays. What if a portion of those requirements were classroom-focused instead."
John Marwick, principal of Forrest Hill School on Auckland's North Shore, said adding a week or two at the start of the school year could cause problems with longer terms.
"That would be very difficult for 5- and 6-year-olds to stay focused for that amount of time."
He recalled that a mid-term break was needed for the middle term of the old three-term year.
Teachers' union NZEI objected to Willis' plan.
National secretary Paul Goulter said he was disappointed the sector hadn't been consulted over the proposed changes.
"Unfortunately she seems to ignore the reality which is that teachers, because of the pressures that are on them, actually need these breaks. Lots of the time these breaks are taken up catching up with work they have been forced to hold over because of the staffing crisis in schools … they don't have time to do this work during the school year."