Unix timestamp to days, hours, minutes

Question

So, I have a field in my users table named last_active which updates every time a user reloads a page.
It\'s stored in unix timestamp.

I would like

Answer 1

After finding dozens of broken or half-there solutions, I built the following function for UNIX timestamps.
You can limit the detail level ...

echo timeDiff(1350297908); will show "5 minutes, 42 seconds ago".
echo timeDiff(1350297908, 1); will just show "5 minutes ago".

function timeDiff( $from, $levels=7 ){  
    $now = time();
    $diff = ($from > $now) ? $from - $now : $now - $from;
    $status = ($from > $now) ? ' away' : ' ago';
    $times = array(31536000, 2628000, 604800, 86400, 3600, 60, 1);
    $words = array('year', 'month', 'week', 'day', 'hour', 'minute', 'second');
    $str = array();
    foreach ($times as $k=>$v){
        $val = floor($diff/$v);
        if ($val) {
            $str[] = $val .' '. $words[$k] . ($val==1 ? '' : 's');
            $levels--;
        }
        $diff %= $v;
        if ($levels==0) break;
    }
    return implode(', ', $str) . $status;
}