
  -spec erlang:universaltime_to_localtime(Universaltime) -> Localtime
                                             when
                                                 Localtime ::
                                                     calendar:datetime(),
                                                 Universaltime ::
                                                     calendar:datetime().

  Converts Universal Time Coordinated (UTC) date and time to local
  date and time in the form {{Year, Month, Day}, {Hour, Minute,
  Second}} if supported by the underlying OS. Otherwise no
  conversion is done, and Universaltime is returned. Example:

    > erlang:universaltime_to_localtime({{1996,11,6},{14,18,43}}).
    {{1996,11,7},{15,18,43}}

  Failure: badarg if Universaltime denotes an invalid date and
  time.
