Facebook like reletive time in PHP

reletive.php

function getmychattime($datetime){
	$timestamp = strtotime($datetime);
	$now = time();
	$diff = $now - $timestamp;
	if ($diff < 60){
        return date('g:ia',$timestamp);
    }
    $diff = floor($diff/60);
    if ($diff < 60){
        return date('g:ia',$timestamp);
    }
    $diff = floor($diff/60);
    if ($diff < 24){
        return date('g:ia',$timestamp);
    }
    $diff = floor($diff/24);
    if ($diff < 7){
        return date('D',$timestamp);
    }
    if ($diff < 30)
    {
        return date('d/m',$timestamp);
    }
    $diff = floor($diff/30);
    if ($diff < 12){
        return date('d/m',$timestamp);
    }
    $diff = date('Y', $now) - date('Y', $date);
    return sprintf($diff > 1 ? '%s years ago' : 'last year', $diff);
}