Four primary schools are giving families the choice of pupils starting lessons at different times of the day.
Four Plymouth schools are taking part in the month-long pilot scheme
In a government-funded experiment, pupils in Plymouth, Devon, can start formal lessons at 7.45am or 11am, instead of 9am.
The project is being piloted over a four-week period as part of the "extended schools" initiative.
If the scheme to help working families is successful it could be used in other schools across the country.
The scheme, which started on Monday, is being run at Southway Primary school, Tamerton Vale Primary, Langley Infant school and Langley Junior school.
And pupils who start the school day earlier will finish formal learning earlier - with the remainder of the day being given over to "fun" activities.
The initiative is being tested by pupils in Year 2 (six and seven-year-olds) and Year 5 (nine and ten-year-olds).
The children took tests before the trial and they will be tested again after the four weeks to assess whether their learning capacities have been enhanced by working at different times and taking part in extended activities such as dance and music workshops.
Parents, teachers and pupils will keep diaries of their progress to record any problems such as children being overtired.
Acting head teacher at Tamerton Vale, Sally Cresswell, said the idea was to offer wrap-around care and to ft with the extended schools agenda.
"The idea is that you tailor it to fit with working parents and parents who aren't working," she said.
"We're also reflecting on what is best for children in terms of learning.
"Do children learn better if they opt for more exciting activities at the start or beginning of the day?
"And it's finding out what is the best time of the day for children to be learning."
The results of the pilot will be published in October.