php 返回相对时间，如：20分钟前，3天前

感兴趣的小伙伴，下面一起跟随编程之家 jb51.cc的小编来看看吧。
经测试代码如下：

/**
 * 友好时间显示
 *
 * @param 
 * @arrange (编程之家) jb51.cc
 **/
function plural($num) {
 if ($num != 1)
  return s;
}
 
function getRelativeTime($date) {
 $diff = time() - strtotime($date);
 if ($diff<60)
  return $diff .  second . plural($diff) .  ago;
 $diff = round($diff/60);
 if ($diff<60)
  return $diff .  minute . plural($diff) .  ago;
 $diff = round($diff/60);
 if ($diff<24)
  return $diff .  hour . plural($diff) .  ago;
 $diff = round($diff/24);
 if ($diff<7)
  return $diff .  day . plural($diff) .  ago;
 $diff = round($diff/7);
 if ($diff<4)
  return $diff .  week . plural($diff) .  ago;
 return on  . date(F j,Y,strtotime($date));
}