Function for formatting time difference in a human friendly format (e.g. 4h 12m)

time_elapsed.php

<?php

echo time_elapsed(35); // will output 35s
echo time_elapsed(2*60 + 15); // will output 2m
echo time_elapsed(2*60 + 15, TRUE); // will output 2m 15s
echo time_elapsed(2*60*60 + 15*60); // will output 2h 15m
echo time_elapsed(2*24*60*60 + 15*60*60); // will output 2d 15h
echo time_elapsed(2*24*60*60 + 15*60*60 + 3*60); // will output 2d 15h 3m
echo time_elapsed(5*7*24*60*60 + 2*24*60*60 + 15*60*60 + 3*60); // will output 5w 2d 15h 3m

function time_elapsed($seconds_difference, $show_seconds_in_result = FALSE){
	$bit = array(
		'year'  => $seconds_difference / 31556926 % 12,
		'w'     => $seconds_difference / 604800 % 52,
		'd'     => $seconds_difference / 86400 % 7,
		'h'     => $seconds_difference / 3600 % 24,
		'm'     => $seconds_difference / 60 % 60,
	);

	if ($show_seconds_in_result || $seconds_difference < 60)
		$bit['s'] = $seconds_difference % 60;

	$ret = array();
	foreach($bit as $k => $v){
		if($v >= 1)
			$ret[] = $v . $k;
	}

	return join(' ', $ret);
}

?>