// package constructor, only called by Fields.
DateField(OdfElement odfElement) {
TextSpanElement spanElement = ((OdfFileDom) odfElement.getOwnerDocument()).newOdfElement(TextSpanElement.class);
odfElement.appendChild(spanElement);
dateElement = spanElement.newTextDateElement();
OdfNumberDateStyle dateStyle = newDateStyle();
String dateStyleName = dateStyle.getStyleNameAttribute();
dateStyle.buildFromFormat(DEFAULT_DATE_FORMAT);
dateStyle.setStyleNameAttribute(dateStyleName);
dateElement.setStyleDataStyleNameAttribute(dateStyle.getStyleNameAttribute());