Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/12/15/adding-suffixes-to-month-names-and-years-in-the-datefield-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white">

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="monthSymbol:">
                <mx:TextInput id="monthSuffix" maxChars="3" />
            </mx:FormItem>
            <mx:FormItem label="yearSymbol:">
                <mx:TextInput id="yearSuffix" maxChars="3" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:DateField id="dateField"
            monthSymbol="{monthSuffix.text}"
            yearSymbol="{yearSuffix.text}" />

</mx:Application>

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