code: public static Calendar parse(String dateString) throws ValueFormatException
     {
        try
        {
           return ISO8601.parseEx(dateString);
        }
        catch (ParseException e)
        {
           throw new ValueFormatException("Can not parse date from [" + dateString + "]", e);
        }
        catch (NumberFormatException e)
        {
           throw new ValueFormatException("Can not parse date from [" + dateString + "]", e);
        }
     }
docs: Parse string using possible formats list.
  
  @param dateString
  - date string
  @return - calendar
  @throws ValueFormatException