Students in Hawaii's public schools will head back to their classrooms as early as July 30 and finish school May 26 under a new calendar that shortens winter and spring breaks to lengthen summer vacation.

The Board of Education is boosting summer vacation to nine weeks, to make it easier to offer summer school and give teachers more time to attend programs of their own.

Starting the academic year in midsummer also ensures the first semester is completed before winter break, officials said.

“;What I like about it is that the semester ends at Christmas break,”; said Steve Franz, principal of King Kamehameha III Elementary in Lahaina. “;I don't know of any traditional calendar that does. And I like the way the rest of our breaks are between our quarters.”;

Students will also have two more weeks of instruction before they face high-stakes testing in April, as compared with the previous calendar. They will have a week's vacation in early October, two weeks at Christmas and a week in mid-March.

It is the second major calendar change in three years for the public schools. In 2006-07 the system shifted to one statewide calendar to simplify things for families and streamline payroll and administration. That calendar had breaks of a week in the fall, three weeks in winter and two weeks in the spring, plus a seven-week summer.

The rationale was that students would retain their knowledge through a shorter summer, requiring less review when they returned. The longer breaks during the year allowed students to catch up academically or go on school trips. Some teachers felt the intermittent breaks gave them a chance to refuel and recharge from a stressful job.

But the number of campuses that offered summer school dropped precipitously, making it harder for students to earn credits at a time when graduation requirements were being raised. The class of 2010 must earn 24 credits to graduate, up from 22 previously.

Only 41 schools plus the online e-School offered summer classes in 2007, the year after the calendar went into effect, down from 76 the previous year. This summer, even fewer campuses, just 46, offered classes.

“;Hopefully, next year we'll have more schools participating and offering summer school,”; Department of Education spokeswoman Sandy Goya said Friday.

Most other school systems and colleges are on vacation from mid-June to mid-August. Some teachers argued that would make more sense for Hawaii's public schools, too, rather than letting kids out on May 26.

“;Under this calendar, we will remain largely out of step with the rest of the academic community,”; Lahainaluna High School teacher Ashley Olson told the school board. That makes it harder for teachers to attend summer session courses and conferences, she said.

She also pleaded with the board to “;keep us out of the sweltering classrooms in July and August.”; “;May and June are still bearable despite the chronic absences of any climate control in the vast majority of our classrooms,”; she testified.

But the board voted 10-1 last year to revise the calendar. Board member Breene Harimoto opposed the move, noting that many principals favored the previous calendar for academic reasons.

“;We should have let it run its course until evidence showed otherwise,”; he said last week.

Although the official start date for students is July 30, many schools have put that off until Aug. 3, a Monday. Campuses have flexibility to shift a few days here and there by choosing “;planning and collaboration”; days for their teachers.