Students at Jefferson County schools that operate on a year-round calendar head back to school tomorrow. They include five elementary schools and one high school.JCPS spokesperson Lauren Roberts says those schools are in session for 45-days at a time, with two-week intercessions in between, and a longer break in late spring/early summer."During those intercessions, students can receive supplemental services or enrichment activities but its an opportunities that provides more frequent breaks but also allows them to retain the information they’ve learned during that 45 day period," says Roberts.Engelhard and Portland Elementary Schools had been running on a year-round schedule, but this year they return to the traditional calendar.