As Miami Dade County moves into preparation and planning for the next budget year, Mayor Carlos Gimenez considers raising taxes to help fund libraries, parks and cultural institutions, provided voters first endorse the concept in a straw poll vote this summer. Without additional funding, libraries are currently proposed for a 35 percent reduction in hours countywide with significant staff reductions as well. “Having a library open four hours a day, for four days a week, is really not having a library open,’’ said here.