php判断之前的时间段

<?php
/**
 *
 +--------------------------------------------------------------------
 * Description 友好显示时间
 +--------------------------------------------------------------------
 * @param int $time 要格式化的时间戳 默认为当前时间
 +--------------------------------------------------------------------
 * @return string $text 格式化后的时间戳
 +--------------------------------------------------------------------
 * @author yijianqing
 +--------------------------------------------------------------------
 */
function mdate($time = NULL) {
   $text = &#39;&#39;;
    $time = $time === NULL || $time > time() ? time() : intval($time);
    $t = time() - $time; //时间差 （秒）
    if ($t == 0)
        $text = &#39;刚刚&#39;;
    elseif ($t < 60)
        $text = $t . &#39;秒前&#39;; // 一分钟内
    elseif ($t < 60 * 60)
        $text = floor($t / 60) . &#39;分钟前&#39;; //一小时内
    elseif ($t < 60 * 60 * 24)
        $text = floor($t / (60 * 60)) . &#39;小时前&#39;; // 一天内
   elseif ($t < 60 * 60 * 24 * 3)
        $text = floor($time/(60*60*24)) ==1 ? &#39;昨天 &#39; . date(&#39;H:i&#39;, $time) : &#39;前天 &#39; . date(&#39;H:i&#39;, $time) ; //昨天和前天
    elseif ($t < 60 * 60 * 24 * 30)
        $text = date(&#39;m月d日 H:i&#39;, $time); //一个月内
    elseif ($t < 60 * 60 * 24 * 365)
        $text = date(&#39;m月d日&#39;, $time); //一年内
    else
        $text = date(&#39;Y年m月d日&#39;, $time); //一年以前
    return $text;
}
?>