code: public DateTime toDateTime(Element el, String attributeName, DateTime defaultValue) {
  
  	String value = el.getAttribute(attributeName);
  	if (value == null) return defaultValue;
  	DateTime dtValue = Caster.toDate(value, false, null, null);
  	if (dtValue == null) return defaultValue;
  	return dtValue;
      }
docs: reads a XML Element Attribute ans cast it to a DateTime
  
  @param el XML Element to read Attribute from it
  @param attributeName Name of the Attribute to read
  @param defaultValue if attribute doesn't exist return default value
  @return Attribute Value