$shoutDate = date('Y-m-d',$shoutTime);
if ($shoutDate == date('Y-m-d'))
    return date('H:i',$shoutTime);

if ($shoutDate == date('Y-m-d',mktime(0,date('m'),date('d') - 1,date('Y'))))
    return 'yesterday';

return gregoriantojd(date('m'),date('d'),date('y')) - gregoriantojd(date('m',$shoutTime),date('d',date('y',$shoutTime)) . ' days ago';