"It would take too much time"
Have you tried to search for the data in any search engine? And then tried to interpret a calendar out of the garbage that is the result of that search?
I know there are services available for TV station programs (usually per country), but AFAICS these are filled with the calendars supplied by the TV stations, not from something 'simple' as a search-engine result.
I wouldn't know where to start getting all radio station program info, and neither what region to 'limit' the search to, there will be several thousands of stations to process, nor parse the (often even hardly human comprehensible) program information, if that is available.
Guess I'm not alone in this assessment...