>>714828248It very much depends on your definition of 'classic' but I would be pretty reluctant to describe anything written in the year 1900 as 'classical' and would be extremely surprised to hear that a 'classic literature' course in any respectable institution would include something like Wizard of Oz or Frankenstein in its syllabus.
Traditionally, when used without a secondary qualifier (eg: 'Classic children's story' or 'classic Victorian novel') the term 'classic' or 'classical' describes works that range from ancient. (Odyssey/Iliad, Metamorphosis, Oedipus) to middle ages (Arthurian Legend(s), Canterbury Tales, Don Quixote, Faustus). I think we are getting to a point where 18th century literature is colloquially starting to be considered 'classic' if it is not explicitly part of the Romantic movement.