This is very simple.
but date format(Y-m-d) is very important.

	<script class="brush: php" type="syntaxhighlighter">
	$date = array();
	$date[0] = '2011-04-10';
	$date[1] = '2009-04-01';
	$date[2] = '2010-01-03';
	$date[3] = '2011-08-04';
	arsort($date);
	</script>

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