This year's post-primary transfer tests will be held at least two weeks later than usual.
The tests are normally taken by pupils on five consecutive Saturdays beginning in early November.
However, the first test in 2020 will not be held until Saturday 21 November.
Testing organisations AQE (Association of Quality Education) and PPTC (Post Primary Transfer Consortium) said the delay should allow pupils extra time in school to prepare for the exams.
Most grammar schools in Northern Ireland have been using one or both tests to select pupils since 2008.
That was when the 11-plus exam run by the Department of Education was scrapped.
AQE said it had originally intended to postpone its tests until January 2021, but this was not possible due to the Department of Education's timescale for the wider process enabling all pupils to transfer to post-primary schools.
"AQE acknowledges the minister's firm support for academic selection and both parties examined in good faith a number of differing options," AQE said in a statement.
"However, for logistical reasons, it was reluctantly recognised that such an accommodation would not be possible and the department was unable to accede to AQE's proposal."
The tests run by AQE will now take place on Saturday 21 November, Saturday 28 November and Saturday 12 December.
The test run by PPTC will be held on Saturday 5 December with a reserve test on Saturday 19 December.
The transfer tests are used by the vast majority of grammar schools in Northern Ireland to select pupils and there were about 16,000 entrants in 2019/20.
However some parents of pupils currently in Primary Six had expressed concerns that with schools closed due to the coronavirus pandemic, their children would not receive adequate preparation for the tests.
Education Minister Peter Weir had previously changed departmental policy to allow schools to prepare children for the tests.
He said Monday's announcement would provide pupils, parents and teachers with the "clarity" they had been calling for.
"More importantly, I hope that it will remove any stress that pupils and parents might be feeling and provide reassurance in terms of being able to plan and work towards the new dates that have been announced," he added.
Registration for the AQE tests will open online on Thursday 14 May while PPTC will open registration on its website on 1 June.
However PPTC acknowledged in a statement that the situation regarding how schools would run in the autumn was still unclear.
"There are still many unknowns regarding what will be possible right across society in the late autumn," the organisation said.
"PPTC recognises that its plans may be affected by the unfolding situation."
In a letter to primary school principals, AQE also recommended parents paid test fees online.
It said: "The fee to sit the assessment this year is £55 of which £35 is non-refundable if the CEA tests were to be, unfortunately, cancelled due to coronavirus."
Children eligible for free school meals do not pay an entry fee for the AQE tests and there is no charge to parents for the test run by PPTC.
Providing the transfer tests can go ahead in November and December as planned, children will get their results at the end of January 2021.