code: @Nullable
    public static ZonedDateTime getDateTimeFromW3COrRFC822 (@Nullable final String sDate)
    {
      final OffsetDateTime aDateTime = getDateTimeFromW3C (sDate);
      if (aDateTime != null)
        return aDateTime.toZonedDateTime ();
  
      return getDateTimeFromRFC822 (sDate);
    }
docs: Parses a Date out of a String with a date in W3C date-time format or in a
  RFC822 format.
  
  @param sDate
  string to parse for a date.
  @return the Date represented by the given W3C date-time string. It returns
  <b>null</b> if it was not possible to parse the given string into a
  Date.