code: public static DateTime toDateAdvanced(String str, TimeZone timezone) throws PageException {
  	DateTime dt = toDateAdvanced(str, timezone, null);
  	if (dt == null) throw new ExpressionException("can't cast [" + str + "] to date value");
  	return dt;
      }
docs: converts a Object to a DateTime Object (Advanced but slower)
  
  @param str String to Convert
  @param timezone
  @return Date Time Object
  @throws PageException