A media balancer obtains a master schedule to be used as a basis for generating target schedules, user input specifying one or more target stations for which the one or more target schedules are to be generated, and a duration delta indicating a maximum difference between runtimes of the replacement media items and the one or more scheduled media items. The media balancer selects a media scheduler to identify replacement media items to be substituted for one or more scheduled media items identified in the master schedule and transmits information associated with the duration delta to the media scheduler. The media balancer receives a list of identified replacement media items selected by the media scheduler, and generates the target schedules by replacing scheduled media items with particular replacement media items taken from the list of identified replacement media items.