Advocates of year-round schools argue that they provide three primary benefits:

• More frequent breaks for students and teachers help to prevent burn-out.
• Schools can address overcrowding without building new facilities, by staggering student attendance.
• The need for extensive review and re-teaching at the beginning of a traditional academic year is eliminated, and more time left for teaching new material.

Year-round schools do not alter the minimum number of required school days in an academic year.

For further explanation:

• Is Year-round Schooling the Answer?