Source : Free On-Line Dictionary of Computing

copious free time
     
        (Apple; originally from the introduction to Tom Lehrer's song
        "It Makes A Fellow Proud To Be A Soldier") Used ironically to
        indicate the speaker's lack of the quantity in question; a
        mythical schedule slot for accomplishing tasks held to be
        unlikely or impossible.  Sometimes used to indicate that the
        speaker is interested in accomplishing the task, but believes
        that the opportunity will not arise.  "I'll implement the
        automatic layout stuff in my copious free time."
     
        The phrase is also used for time reserved for bogus or
        otherwise idiotic tasks, such as implementation of bad
        {chrome}, or the stroking of {suit}s.  "I'll get back to him
        on that feature in my copious free time."
     
        [{Jargon File}]
     
        (1994-11-30)