The Supreme Court on Thursday used the case of a Christian mail carrier who did not want to work Sundays to solidify protections for workers who ask for religious accommodations. In a unanimous decision the justices made clear that workers who ask for accommodations, such as taking the Sabbath off, should have their requests honored unless employers show that doing so would result in “substantial increased costs” to the business. The court made clear that businesses must cite more than minor costs — known as “de minimis” costs — to reject requests for religious accommodations at work. Unlike most cases before the court, both sides in the case had agreed that businesses needed to show more.