A group of parents is urging a Bergen County school district to move anunused snow day to Passover this year after officials announced the day would be added to spring break. At least a dozen Glen Rock parents have requested the change so all students can take off on the Jewish holiday, said Liliya Nissen, a mother of two children in the district advocating for the move. Several districts give students a day off for Passover, she said. Public schools in New York City have off for the holiday as part of their spring break this year. “I know that they’re all different,” Nissen said of school dis…