The government is banning term-time days for teacher development - saying schools will need to book those during holidays if needed.
But what are teacher-only days for? Here's what you need to know.
How many teacher-only days do they have?
The Ministry of Education allows up to 10 "call back days" a year, where schools can require teachers to be on site when they are not "open for instruction" - in other words, when students are not there.
Five days can be for general school administration - such as information and whole-school planning for the year ahead - and another five days can be for professional development.
On top of that, since 2023, the ministry has allocated two extra days a year for teachers to plan for changes to curriculum and assessment.
What are teacher-only days for?
For primary teachers, they might involve learning about, and planning for, the new literacy and numeracy requirements. Because many primary-trained teachers are generalists, there could also be learning on specific parts of the curriculum, such as health, science or the arts.
For secondary schools, NCEA curriculum and assessment changes mean departments have had to rewrite a full-year programme across most year levels, as well as entire unit plans, which would cover anything from a few weeks of learning - say, on speeches, citizenship or plant biology - to a full term of lessons.
Within each unit plan, there are individual lessons. If the content is changing (in other words, the "what" of learning) as well as the pedagogy (how the students will be taught and assessed) this requires considerable thought, time, teamwork and coordination to prepare before it can be classroom-ready.
One head of social science at an Auckland secondary school said those planning days were "really important".
"It doesn't matter how long you've been teaching - it's bringing things to the front of mind, it makes it present.
"I take them really seriously as an opportunity for teacher growth and support, which in the end grows students' achievement.
"There's no magic pill that someone can take to help students grow on their own, so we have really structured teacher-only days in our department."
For example, schools may have had a full day preparing for Mana ōrite mō te mātauranga Māori - the plans to give Māori knowledge and ways of being equal status in the New Zealand education system.
This could cover te whare tapa whā - a model of student wellbeing developed by Sir Mason Durie in 1984 - as well as tikanga, te reo and subject-specific approaches to te ao Māori.
Why can't they have teacher-only days during the school holidays?
In fact, many schools do hold teacher-only days just before the Christmas holidays begin, at the end of term four, or at the start of term one.
Associate Minister of Education David Seymour said legally such days are only allowed to be held out of term time unless authorised by the Minister of Education.
In practice, many schools tack teacher-only days onto long weekends or the end of term to minimise disruption to learning, principal Kyle Brewerton told Morning Report.
"We often see that families will take that extra day, so common sense suggests that if we are going to lose a lot of kids - which doesn't make it right, but it happens - then it makes sense that we take that time."
Many teachers - who are often parents themselves - spend the school "holidays" marking, planning or report-writing - or a combination of all three.
On top of this, Teaching Council standards require them to keep up to date on the latest research in their area and/or year level - not possible when in the classroom.
The social science teacher said during the term teachers are "often just trying to fly by the seat of your underpants".
The term-time teacher-only days enabled teams to "take stock, refresh and spend a whole day actually getting some continuity and making some progress".
What does the typical teacher-only day look like?
Different schools have different practices, but many teacher-only days begin with a karakia and waiata.
Depending on the time of year, they will then hear an address from the principal, looking ahead to future terms or the following year.
After that, there might be a whole-school session - for example, on literacy, or raising the achievement of Pacific Island students.
Following a short interval, departments might break off for subject-specific planning and development. In an English department, this could be preparing units and lessons on the new NCEA Level 1 standards, or discussing new texts by New Zealand authors.
After lunch, groups from different departments might come together to plan how to structure lessons and improve student engagement, say, or to integrate grammar, punctuation and vocabulary development into teaching programmes. The instruction "analyse" looks very different in science, compared to English, for example.
How long are teachers there for?
Teachers are required to be on-site for a whole school day - so from 8.30am to 4.30pm.
For those on the PPTA's collective agreement, the school must reimburse teachers for reasonable costs, including childcare, travel and meals. In practice, many schools put on a light meal or provide a packed lunch for teachers.
Why can't teachers do half-days for professional development?
The Auckland teacher points out that attendance is already difficult and students simply would not turn up to a half-day.
"And what do parents do with younger children? A full day allows you to sit in groups and make progress.
"If you're going to be an effective teacher, you need to be present when they're there in front of you. If I've got 35 students, I've got to get round all of them - some may need longer for explanations, others might need extending. You're constantly flying round - so you've got to plan for that."
Why can't teachers do that planning outside of school hours?
Many teachers already do plan late into the evening and at weekends - and many are involved in extracurricular activities like school productions, debating, orchestras and choirs, not to mention sporting groups.
"I work six or seven day weeks," the Auckland teacher pointed out. "On Saturday, I'm out all day with sport, from 9am to 4pm - so that's a day away from family.
"On Sunday, I'm marking and planning for the next week. During the week, we often have meetings after school.
"The life of a teacher is pretty busy if you're fully involved in a school, and all this time when you're coaching, you're not seeing your own children."