Last two years. I have been studying my master in planning school in Canada and most of students came from unrelated undergraduate background such as phycology , economy, social work, agriculture, and English. Ironically, they will call themselves planners after graduating from only 2 years ( M.Sc. Planning).
From my point of view, planning profession's wall has been very low so everyone can claim it and be a planner with out knowing how to read a master plan or work in studios with real planners. I mean by real planner, an individual who is very skillful and well- established in his undergraduate studies, spent 4-5 years working in studios with smart fellows who are capable of reading and analyzing planning problems and coming up with best alternatives that can meet goal and objectives of projects.
Real planners have to understand every issues such as land use, urban design, transportation, environment, urban economy ( not a general one) in addition to technical skills such as using computer programs ( Auto-Cad, GIS) to draw maps so they could reflect all their analysis and ideas on real maps and write good technical reports. Indeed, this is a real product for real planning profession. Planning is not a talk or debate as it is reflected in masters courses, PLANNING IS A REAL PROFESSION.
The only solution I can see for this problem is that master programs in planning should not accept any student out of environmental design field ( Urban and regional planning, Architecture, Landscape architecture, Geography, Civil engineering) Otherwise, they should ask applicants from unrelated undergraduate background to take 2 years upgrading courses before joining planning graduate program.