Am I obligated to pay for a daily parking permit?

Yes. Duration of individual parking sessions per zone is governed by the Ordinance on the Use of Public Parking Lots and Public Garages, which was adopted by the Mayor of the City of Zagreb (Official Gazette of the City of Zagreb 6/14, 18/14, 23/14, 20/15, 23/15, 17/18). Maximum parking time allows the use of public parking lots for all potential customers who have a need to reach the centre of the city.