"We expect that many employees will continue to work 7.5 hours because they are already doing that and that some departments will change their 8 hours workers to 7.5 hours, thereby avoiding any additional cost," city spokesperson Mike Dunn said in an email. "Of course, there are some departments who will actually work 8 hours and pay the extra half hour on a regular basis. We can't, at this point, pinpoint that last group and predict how all of this will work out or the cost of it."