A Monessen, Pa., school posted differing semester starting dates on its several Web sites, so some students arrived a day early for class, officials said. At least 10 students showed up for school at Monessen Elementary Center Monday, unaware the school district changed the opening date to Tuesday, the Pittsburgh Tribune-Review reported Wednesday. \"I thought it doesn\'t look like there\'s quite enough cars here today, but we were early,\" said Tara Yorty, who drove her daughter to school Monday, only to drive her back home. The Monessen City School District did not notify elementary school parents it had changed the start date, and posted different dates on its four Web sites, parents and school officials said. A newsletter sent to parents in the spring listed Aug. 27, Monday, as the first day of school, the newspaper said. Yorty said she received no notification of a change.