Erm

<?php

	echo calculate_time(time(),strtotime("Apr 26, 2006"))."\n";
	echo calculate_time(time(),strtotime("Apr 26, 2007"))."\n";

	function calculate_time($start, $end) {
		$diff = $start - $end;
		if ($diff <= 0) {
			$prefix = '';
		} else {
			
			$prefix = '-';
		}
		$diff = abs($diff);
		$hms = date('H:m:s',$diff);
		$y = (date('Y', $diff) - 1970);
		$w = date('W', $diff);
		if ($y) {
			$y .= ' years ';
		} else {
			$y = '';
		}
		if ($w) {
			$w .= ' weeks ';
		} else {
			$w = '';
		}
		return "$prefix$y$w$hms";
	}
	
?>