Yup...I was being dense:
<?xml version="1.0" encoding="utf-8"?>
<mx:Label xmlns:mx="http://www.adobe.com/2006/mxml"
textAlign="center" creationComplete="setText()">
<mx:Script>
<![CDATA[
import mx.controls.dataGridClasses.DataGridListData;
private function getFormattedDate():String {
var columnMetadata:DataGridListData =
DataGridListData(listData)
var fieldName:String =
columnMetadata.dataField;
var data:Object = data[fieldName];
return df.format(data);
}
private function setText():void {
text = getFormattedDate();
}
]]>
</mx:Script>
<mx:DateFormatter id="df" formatString="DD-MMM-YY"/>
</mx:Label>