Most pupils in Northern Ireland will not be returning to school in the first week of January as planned.
Primary school pupils will be taught remotely until 11 January, after which they will return to the classroom.
For some post-primary pupils (Years 8-11), online learning will be in place for the entire month of January.
Childcare settings including those attached to schools, pre-school facilities, nurseries and special schools will be open as usual.
Schools will accommodate vulnerable children and the children of key workers from the start of term.
Education Minister Peter Weir said the action was in response to the level of Covid-19 transmission and high case numbers.
On Wednesday, Northern Ireland reported a record 2,143 cases in a 24-hour period.
What else is changing?
For post-primary pupils in Years 12 to 14 - the GCSE and A-level years - they will return to school after the first week of January.
Exams due to take place in January will still go ahead in line with public health guidance, and schools will have flexibility to give face-to-face teaching to students sitting exams.
Youth Service provision, which focuses on the social and development needs of young people, will be stood down until the end of January, with targeted services moving online.
The decision on schools comes after discussions between the Department of Education, Department of Health, Education Authority and the Public Health Agency.
Mr Weir said he had consulted the chief scientific officer and the chief medical officer, and the move was in response to "unprecedented levels of positive Covid-19 tests since Christmas".
"I must stress that these decisions are not made lightly as I know the negative impact on children's learning and mental health and well-being of not being in school," he added.
Mr Weir previously said schools would reopen in the first week of January.
Speaking to BBC's Good Morning Ulster on Thursday, he said decision making had remained consistent with scientific advice throughout the pandemic.
"Whenever announcements were made a couple of weeks ago, they were completely compatible with the advice we were getting from the experts," he said.
Martine Mulhern, principal of St Cecilia's College in Londonderry, welcomed the decision from the education minister but said it should have been taken before the Christmas break.
Speaking to BBC Radio Foyle, Mrs Mulhern said: "We could have had the children prepared for what was to come and I think it was an opportunity missed."
Mrs Mulhern said key worker parents must be made aware that their children can come to school.
"We want to ensure sure those children can still come to school so those individuals can still do the invaluable work to keep us all safe," she added.
'Plans torn to shreds'
Lori Campbell, who is a mum of four from Derry, has said she is not happy that her children will not be returning to school as planned.
"I have four children here at home and they each attend three different schools at four different levels of their education.
"Not attending school has impacted them greatly, not only in their learning but also in their social and emotional wellbeing," she said.
Mrs Campbell, who works as a child minder, has said her previous experience of remote learning impacted her as a parent as she works predominately from home.
"I have to juggle being a step-in school teacher with my children who are still in primary school, as well as the needs of children I look after when I am working."
She added: "I am sitting here, like many other people on New Year's Eve having had a plan for Monday morning for my children to go back to school, a plan for my working week and that plan has just been torn to shreds."
Gerry Murphy, northern secretary for the Irish National Teachers' Organisation, said it was the "right decision" and it would give "the entire system a chance to wait for a safer return".
However, he added the decision was "entirely foreseeable" and the minister could have "announced it last week in the assembly".
Sinn Féin assembly member John O'Dowd, who is a former education minister, also said it was a "belated announcement".
"It does reflect how serious the situation is in regards to our public health and the pressure that is currently on our hospitals.
"I'm a parent and I am also a legislator, and I believe the best place for our children is in schools but only if it is safe to do so.
"It is currently not safe to do that."
Chris Lyttle, chair of the NI Assembly's education committee, acknowledged the minister had a "extremely difficult challenge" but "we really need more timely decisions to avoid this type of distressing situation".