So, exactly what is the difference between the traditional and the year round academic calendars?  According to an article posted on Kidsource.com, ERIC Clearinghouse on Teaching and Teacher Education explains the concept of the year round school calendar is as follows:  

     Year-round education (YRE) is a concept which reorganizes the school year to provide more continuous learning by spacing the long summer vacation into shorter, more frequent vacations throughout the year (Johnson, 2000). Year-round schools may be on a single-track or multi-track schedule. A single-track schedule generally calls for an instructional year of 180 days, with short breaks (or inter sessions) interspersed throughout the school year. A multi-track schedule staggers the instructional and vacation/intersession periods of each track throughout the entire year, so that some students are receiving instruction while others are on vacation.

     For example, in a single-track 45/15 design, the year is divided into four nine-week terms separated by three-week vacations or intersessions. All students and teachers attend school for nine weeks (45 days), then are on a three-week vacation (15 days). This sequence is repeated four times each year. Alternatively, in a multi-track 45/15 design, students are normally divided into four groups. During a 12-week period, all students receive nine weeks of instruction and three weeks of vacation, but only three of the four groups are in school at one time, while the fourth group is on vacation. When the vacation group returns, another group leaves for a three-week vacation.

     Thus, in the multi-track configuration, the enrollment in existing schools can be increased by one-third, or, alternatively, current class size can be reduced (Minnesota, 1999). Moreover, money which would otherwise have been spent on construction of new schools may be utilized to pay additional salary to teachers who elect to extend their contract on the multi-track year-round schedule. Therefore, the annual income of these teachers can conceivably be increased by one-third, and the effective supply of teachers can be increased by one-third (Liebman, 1959).

     If you are tackling a choice between the traditional or year round school calendar options this page is designed to provide you with informative links that examine both the pros and cons of an extended school calendar.