From the beginning of the next academic year, all 12 of the Bailiwick's primary schools will operate for six hours and 15 minutes a day.
Head of Primary Leadership and Development Kim Hutchison says this will give pupils equal educational opportunities, regardless of the site they attend.
"We are seeking to bring consistency across primary schools to the number of hours in the school day.
The important part from an education equity perspective is that all our mainstream primary schools will operate a six hour and 15 minute day."
A Guernsey mum contacted Island FM, concerned that her child's school day would be reduced by 15 minutes.
She brands the decision hypocritical.
"A lot of parents are concerned about the junior children getting less hours from September.
We are often reminded how being just five minutes late for school equates to three school days missed a year.
There was no consultation with parents about the impact it would have on us."
The mum was concerned about traffic congestion too, but Kim Hutchinson says this has been factored in to the plans:
"All schools will not start and finish at exactly the same time.
For example, there will be a variance between 8.30am-9am for school start times and 2.45pm and 3.15pm for school finishing times, and it has been the schools themselves that have decided which is best for them.
Given that start and finish times will still be staggered, we do not anticipate increased congestion issues, but each school headteacher will consider this and any measures they need to put in place.
There is also only one bus time change at a single school."
A letter has been sent to parents, informing them of the changes that come into effect in September 2024.