A divided School Committee will continue scheduling 10 half days each school year through 2015. Mayor Donna Holaday had proposed eliminating at least three of the half days, but that idea was turned down following objections from the teachers union, which argued that the half days are needed to comply with new state initiatives and improve student achievement. The issue came to the forefront late last month because the School Committee had to approve school calendars for the next two academic years (2013-14 and 2014-15) in order to plan school building projects around summer vacation schedules. Rather than eliminate the half days, the School Committee approved a pre-Labor Day start to the 2013-2014 school year of Aug. 28. The following year, classes will begin after Labor Day, on Sept. 4, 2014.