The secondary teachers union has announced more industrial action over stalled pay talks with the Ministry of Education.
The Post Primary Teachers Association says its members will refuse to teach one day a week during eight of the nine weeks of next term.
Years 12 and 13 are not included in the action, which will affects Year 11 students once, Year 10 students three times and Year 9 students four times.
The union has also told members not to work or attend training after 5pm or during weekends or school holidays.
The action follows a one-day strike by union members last week.
The Secondary Principals Association says it will be up to schools to decide whether to send home students affected by the action.
But it says it will be easier to keep students at schools and hire relievers to teach them.
It says it wants the dispute resolved before it harms students' NCEA preparations.
Secondary school pupils begin holidays at the end of the week. School resumes in October.
The union wants a pay rise of 4%. The Ministry of Education is offering 1.5% in the first year and 1% the next.