<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/04/28/aligning-the-selected-date-in-a-datefield-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.events.ItemClickEvent;

            private function init():void {
                dateField.selectedDate = new Date();
            }

            private function toggleButtonBar_itemClick(evt:ItemClickEvent):void {
                dateField.setStyle("textAlign", evt.item.label);
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:ToggleButtonBar id="toggleButtonBar"
                selectedIndex="1"
                itemClick="toggleButtonBar_itemClick(event);">
            <mx:dataProvider>
                <mx:Array>
                    <mx:Object label="left" />
                    <mx:Object label="center" />
                    <mx:Object label="right" />
                </mx:Array>
            </mx:dataProvider>
        </mx:ToggleButtonBar>
    </mx:ApplicationControlBar>

    <mx:DateField id="dateField"
            width="200"
            textAlign="center"
            initialize="init();" />

</mx:Application>