Copy editing (also copy-editing or copyediting, sometimes abbreviated ce) is the process of reviewing and correcting written material to improve accuracy, readability, and fitness for its purpose, and to ensure that it is free of error, omission, inconsistency, and repetition. In the context of publication in print, copy editing is done before typesetting and again before proofreading, the final step in the editorial cycle.
All hail lord google and all knowing wikipedia
( the time it takes is somewhat dependent on the material to copy edit i.e. how lengthy it is )