   @type std_offset  :: integer
 
   @doc """
-  Builds a new date from propletic year, month and day of month.
+  Builds a new date from proleptic year, month and day of month.
   """
   @callback date(year, month, day) :: {:ok, Date.t} | {:error, atom}
 

  Only supports converting date times which are in the ISO calendar,
  attempting to convert date times from other calendars will raise.

  WARNING: the ISO8601 does contain the time zone nor its abbreviation,
  which means information is lost when converting to such format. This
  is also why this module does not provide a `from_iso8601/1` function,
  as it is impossible to build a proper `DateTime` from only the

  @doc """
  Parses the extended "Date and time of day" format described by ISO8601:2004.

  Raises if the format is invalid.

  ## Examples

