Schools in Brighton and Hove are extending the October half-term break to allow parents to access cheaper holidays.
The city council said the new two-week October half-term, to begin in 2017, will help families to spend time together without children missing school.
It said the break, from 14 to 29 October, had been designed to give families more flexibility to go away outside the peak summer holiday period.
The changes in school holidays have been made by adjusting the start and finish dates of the three main terms at all state primary and secondary schools in the area, and will not lead to any reduction in the number of overall teaching days.
The council has said the new term dates will be reviewed after a two-year trial period.