php实现求相对时间函数

<?phpfunction relativeTime($time = false, $limit = 86400, $format = 'g:i A M jS') {  if (empty($time) || (!is_string($time) & amp; & amp;  !is_numeric($time))) $time = time();  elseif (is_string($time)) $time = strtotime($time);  $now = time();  $relative = '';  if ($time === $now) $relative = 'now';  elseif ($time > $now) $relative = 'in the future';  else {    $diff = $now - $time;    if ($diff >= $limit) $relative = date($format, $time);    elseif ($diff < 60) {      $relative = 'less than one minute ago';    } elseif (($minutes = ceil($diff / 60)) < 60) {      $relative = $minutes . ' minute' . (((int)$minutes === 1) ? '' : 's') . ' ago';    } else {      $hours = ceil($diff / 3600);      $relative = 'about ' . $hours . ' hour' . (((int)$hours === 1) ? '' : 's') . ' ago';    }  }  return $relative;}