Dundee pupils could finish school at different times on different days.
The Courier understands that a major shake-up of the school day is being contemplated behind closed doors by the council.
The move, which is thought to be at the prompting of head teachers, would result in the number of periods taught at Dundee secondary schools shift to 33 a week.
In all but one secondary school, that could result in the end of the school day shifting from 3.30pm to either 3.50pm or 3pm, for example.
Education convener Stewart Hunter confirmed the council were looking at the matter again but insisted he would consult with parents before any plans were voted on.
The proposals, which are thought to be at an early stage but could be debated as early as June 22, were previously brought forward at the end of 2011.
At that time, the proposal was knocked back as furious parents feared the spectre of having to leave work early to collect their children.
There were also worries that changes to lunchtimes would have implications for catering and cleaning staff.
In his previous report to councillors, director of education Michael Woodsaid the shift would bring substantial learning benefits, as well as harmonise the timetables of schools across Dundee.
He also said it would provide greater time for physical education, as well as allow a “good balance of study” for pupils.
Labour education spokesman Laurie Bidwell said the plans had previously been withdrawn following “hostility” from parents and teachers.
He added: “Basically it would mean there will be three longer days and two shorter days.
“Parents would have to deal with that, and for some people their life is arranged around either collecting their kids from school or being home when their kids get home.
“It would just affect secondary pupils, but many parents have children at both, which would make arrangements even more complicated.”
A Dundee City Council spokesman said: “Schools are continually reviewing the curriculum and discussions on a number of curricular issues have taken place recently with head teachers.”