Strike action by university lecturers is set to affect about 50,000 students in Northern Ireland.
Queen's University and the University of Ulster will be hit by the stoppage over changes to pensions.
Lecturers will also take part in a UK wide stoppage on Thursday.
Their union said the action was unavoidable after the Employers Pension Forum, which represents the universities, rejected talks.
The national president of the University and Colleges Union (UCU), Alan Whitaker, said they wanted to get the employers back into discussions.
"It is a dispute that can be settled, but we need those negotiations," he said.
"That's what the strike is planned to do, if we can get the employers talking to us again then we will have achieved what we're trying to do.
"We're hoping that the strike will be pretty solid at Queen's University and the University of Ulster."
In a statement a University of Ulster spokesperson said: "The proposed strike action in NI on 21/3 and across the UK on 24/3 follows two national ballots on pay and pensions.
"The turnout at the ballot on both of these issues was less than 30% of UCU's membership, at Ulster the turnout was even less.
"The university anticipates normal business for staff and students on both of the proposed days of action."
Employers Pensions Forum spokesperson Professor Brian Cantor said "an enormous amount of work" had gone into the scheme and the universities were "disappointed" by the decision to strike.
"The changes are in response to the increasing costs to the scheme from improved longevity," he said.
"The retention of a final salary pension for all existing USS members is an exceptionally good benefit and the career average scheme for future employees is in line with what looks to become the norm in all sectors."
Professor Cantor said the UCU was ignoring the three years of negotiations and "seeking to overturn the decisions of the USS Trustee Board, by refusing to attend meetings to ratify, most recently last Thursday".
"This strike action is very damaging to students," he added.