School holidays were originally planned to fit the needs of the farming calendar.
It allowed pupils to be able to take time off during the busy period of summer and help with the harvest.
According to Education Minister Ruairi Quinn, the scheduling of school holidays is agreed between school management, the teachers' unions and the Government.
Mr Quinn said recently in the Dail that the start and end of the school year is not standardised.
However, schools must provide a minimum of 167 teaching days at post-primary level and 183 teaching days at primary level.