Thousands of Auckland school students have given up part of their holidays to catch up with the learning they lost in the city's two Covid-19 lockdowns.

Teachers at most of the city's high schools have also volunteered to keep working for at least some days during the two-week "break" before the final countdown to a delayed start of exams for the National Certificate of Educational Achievement (NCEA), now due to start on November 16.

Waitākere College principal Mark Shanahan laid on free Subway lunches to entice about 200 NCEA students back to class - but, like most schools, he has scheduled classes only in one week of the break so that students and teachers still get next week off.

The college's head of English, Jayne Fugmann, said she targeted "borderline" students who might not get through NCEA without extra help.

"For my class, I have sent a letter home explaining who I wanted to come in for all the kids who are borderline or behind, as well as the others who choose to come in," she said.

"Most of them are here. It's not compulsory, I think it's more that they know we are coming from a position of care. We are not saying, 'You must come in.' We are here to help."

School buses are not operating, so students walked, caught the train or were dropped off by their parents.

While his two younger siblings enjoyed the first day of the holidays, Year 11 student Bryn Rogers went back to school as usual.

"My brother went to a friend's house, my sister's having a sleepover, and I'm at school doing work," he said.

"I'm behind in English, which is why I'm here. I'm resitting a test because I didn't pass.

"It was a bit stressful, and my work ethic is not very good out of school, so that's the main reason why I'm so behind," he said.

"I could do it at home, but I'm here to ask Miss how to do things. It makes me focus more when I'm at school."

Another Year 11 student, Nathaniel Askew, said he was feeling "quite confident" because he already has 54 or 55 credits out of the 64 that he needs to get this year, after the Government gave all level 1 students up to 10 bonus credits towards the required 80 after the first lockdown plus up to a further six in Auckland after the second lockdown.

Students at levels 2 and 3 get up to eight bonus credits for the March lockdown plus up to a further four in Auckland for the August closure.

"I'm feeling fine with coming in," Nathaniel said. "Only I made the decision kind of last-minute, my mum just dropped me off."

He is writing a speech about artificial intelligence which he needs to deliver in the first week of next term.

Raina Chand, also in Year 11, has written her speech about body image over the past few weeks but didn't have time to present it before the term ended. She picked up three NCEA credits by presenting it to her teacher today.

Year 12 student Dominic Hopewell said he did less work during the lockdown than he would have done at school, so needed to catch up.

"I definitely feel like I fell behind during the lockdown on my general knowledge of the source work and stuff that we needed for exams, and in general I lacked a bit of motivation," he said.

Year 13 student Tajae Numa-Eru is working through the holidays as a casual worker for a company that is busy supplying hand sanitiser and soap, so today was the only day she could get in to the college.

"I'm like a big procrastinator, so lockdown was not good for me, so I didn't feel like doing any work. It's catching up with me now, it's all our standards being jammed into the end of the year," she said.

Annelise Brown and Andee Raven Kenept, also in Year 13, feel robbed of a last year of school that they had been looking forward to.

Annelise lost a whole unit of work because she had been rehearsing for a production which could not be performed in the first lockdown, and now feels that there's no time to learn anything deeply.

"We are still expected to do the same amount of work in a smaller amount of time, which is making it difficult to achieve higher grades," she said.

Andee said there was so much pressure to keep up with schoolwork that there was no time for anything else.

"We didn't have the production or the school trips or the school balls and stuff, so the social aspect has just gone. It doesn't make me like school any more," she said.

"Because it was my last year of school, I was planning to join as much as I could, and because there was nothing this year I felt like I didn't live a full life."