North Carolina House members are trying again to give school systems more flexibility over when they can hold classes. A House education committee on Tuesday passed several measures that would move up start dates or give districts wide-ranging control over their schedules. Current law requires districts to open the school year no earlier than the Monday closest to August 26 and end no later than the Friday closest to June 11. There are exceptions. A uniform calendar law passed in 2004 in response to worries that traditional summer vacations were diminishing. The Senate for years has blocked House legislation to change the rules.