A four-week summer holiday with the extra weeks tagged onto break during the rest of the year is one option being looked out, despite a survey which showed that most people prefered the the current timetable.
Welsh government education minister Jeremy Miles said while public research showed while there was "reasonable contentment" with the timetable there, was openness to change.
A public consultation on whether the summer holidays should be shortened is due to begin in the next academic year.
The Welsh Government commissioned report, carried out by the Beaufort Research company, sought opinions from a total of 13,016 people, including those from parents, carers, businesses, the general public, and from across the Welsh education workforce.
It showed that 76 per cent of parents and carers (76%) s felt the current school year was appropriate for people’s lives nowadays. This finding was echoed by 7-18-year-olds currently in education with 78 per cent agreeing that the current structure of the school year was appropriate.
Of those who work in eduction 78 per cent supported the current timetable.
The fact that it aligned with the English school year was highlighted as beneficial.
Laura Doel, director of school leaders’ union NAHT Cymru, said: “The questions were clearly bias towards pushing the government’s reform agenda. Apart from the initial questions, the status quo was not included in any of the questions giving alternate options. Those who identified current arrangements as their preference were presented with a series of alternative options with no choice of retaining the status quo.
"Even if you were to take this report at face value, it demonstrates that there is no great desire for structural reform of the school year, and it should not be deemed an evidence base on which to make major changes."
"The little evidence available on school holidays shows that countries with much longer summer breaks than Wales have higher levels of attainment and suffer no significant loss of learning. This international evidence is contrary to the reforms being put forward.
"We urge the Education Minister to put plans to move to public consultation on hold until there is a clear evidence base on which to do so.”
Mr Miles said: ""We now have an opportunity to explore these issues in the context of whether the current structure really is the best system to deliver on these shared priorities."