In a move which is designed to assist parents, all schools will take the same holidays and mid-term breaks from next September, under plans which are now being finalised.
The Minister for Education, Mr Dempsey, said the current situation where schools could open or close "with no one tracking them" was "all over the place".
He said agreement on the new "standardised school year" must be in place within "a couple of weeks" to allow school management notify parents about the timetable for next year.
The standardisation of holidays and breaks will apply at primary and secondary level, though second-level colleges will continue to enjoy longer summer breaks.
A leading parents' representative said last night that the planned introduction of a common school year was long overdue as the current situation was a "shambles".
Ms Barbara Johnston of the Congress of Catholic Secondary Schools Parents' Associations said schools had been allowed set their own timetables for far too long. There had, she said, been little or no consultation with parents - even though they were the group most affected.
Many parents, she said, had to juggle work and home commitments in order to cope with a situation where their children were on different mid-term breaks .
Today's meeting with the teacher unions will also consider the question of parent/teacher meetings at more convenient times for parents. Night-time meetings are unlikely in the short term. But it is expected that more meetings will be scheduled outside regular school hours.
The teacher unions have agreed to progress the issue as part of the benchmarking deal.
The Minister warned that there was no question of teachers gaining the 13 per cent due from the benchmarking unless there was agreement on a common school year within weeks.
Mr Dempsey told the Oireachtas Education Committee yesterday: "We cannot pay the benchmarking money unless we make progress. . . it is as simple as that".
Discussions between the Department and the teacher unions on the issue are due today. Yesterday, the Minister hinted there may be some room for manoeuvre to provide some limited local flexibility. But he would no longer tolerate a situation where primary and second-level schools in the one town took holidays at different times.
The Minister said the current haphazard school opening times presented huge difficulties for parents who were often forced to arrange childminding services at short notice.
He wanted to move to a new situation when everyone knew well in advance when schools were open and when they were closed, whether this was for holidays, mid-term breaks or in-service days.
In recent years, both parent groups and school management bodies have expressed concern about the so-called "erosion of the school year" .
Primary students must receive 183 school days per year and secondary school student 167 days but parents and management bodies complain that these requirements are being widely ignored.
A common school year would also allow the Department save money on school transport services and on the running of oral and practical exams.
At present, Mr Dempsey said the Department was paying three times over for oral exams.
It was paying the teacher's regular salary, paying for a substitute when the teacher went to another school for the orals and it was paying a special fee for the orals.
The Minister signalled that this practice would have to stop.
The introduction of the new Junior Cert science course next September remains in the balance after talks between the Department and teacher unions failed to break the deadlock on the issue.
The Teachers' Union of Ireland says it will refuse to implement the new course until conditions in school labs are upgraded.
The ASTI has also expressed concern about the new course at a time when many school labs do not meet health and safety standards.
The Department promised yesterday to provide more funds to upgrade accommodation and equipment .
It will spell these plans out in more detail at a further meeting with the teacher unions shortly.
