With no resolution in sight to the teachers' pay dispute, parents are likely to see their children off school for at least eight days between now and Christmas.
These eight days consist of two strike days (today and an unspecified date early next month) and six days when teachers withdraw from supervision duties, and consequently classes will be cancelled.
Parents should have been told of these disruptions by now, although some said yesterday that they received notice from their local school very late.
While many parents will be angry that their child is losing such valuable time, the situation could get worse before it gets better.
In the middle of next month the central executive council of the Association of Secondary Teachers, Ireland (ASTI) will meet to decide on escalating the dispute.
For parents this could be unnerving because exams could be hit.
As early as February the oral and practical parts of the Leaving Certificate could face collapse if the teachers decide to withdraw their co-operation.
One solution to this would be to use non-teaching staff to correct and administer the papers, a prospect to make most parents shudder.
The eight-day break will affect their parents in different ways. Those starting second-level education can recover the time lost when the dispute ends.
Teachers can reasonably claim they will ensure no pupil in first or second year will fall behind permanently because of their campaign. However, students studying for Leaving Certificate are a different matter.
Mid-November is traditionally a strained time, with many pupils preparing for Christmas exams and pondering their future.
Many will be consulting their career guidance teacher on what to put on their CAO form which is due by February 1st. Many others are filling out forms for British colleges.
All these students are following a weighty two-year curriculum, and by November most are deep into their studies. Many teachers have set their pupils work for the three weeks, but self-discipline will be the crucial factor for most pupils.
Striking teachers will be picketing today so pupils will have little access to them. However, teachers have made it clear that pupils, particularly in sixth year, can contact them during the days when supervision is withdrawn.
Teachers will be in schools on those days (November 16th, 22nd, 23rd, 28th, 29th and 30th), and school managers have emphasised they are expected to remain on the premises even if classes are cancelled.
The six days of supervision withdrawal are unfortunate for students. They will lose three of the five working days of the week starting November 27th.
The National Parents' Council (post-primary) said yesterday this would be especially disruptive as that week becomes severely truncated.
"Some students who are not great at attending school anyway might see it as a whole week off even though classes are only cancelled for three days," said its spokesman, Mr John Whyte.
Next week is not much better. Wednesday's and Thursday's classes will be cancelled. Mr Whyte said this would mean some students skipping lessons on Friday and losing valuable teaching time on top of this week's disruptions.
One principal was sanguine yesterday about the effects of the industrial action on pupils. "Yes, they will lose eight days from school, but all pupils will lose eight days, so nobody will gain an advantage over anyone else," he said.
However, weaker pupils, or those who find it hard to study but who do well in class, will be disadvantaged.
Students taking tough honours subjects, such as maths and Irish, which need more classroom teaching than others, will also lose out.
Another point worth making is that students who can afford to get grind classes will be able to fall back on those teachers during the strike. Schools like Bruce College will be operating throughout this period, and its pupils will not lose any time.
Students who cannot afford grinds are more dependent on ordinary classroom teaching, and eight days without classes represents significant lost time for them.