php计算给定时间之前的函数用法实例

本文实例讲述了php计算给定时间之前的函数用法。分享给大家供大家参考。具体如下：

这里给定一个时间，计算这个时间在多久前，比如：2天前，1年前

    <?php
    function prettyDate($date){
      $time = strtotime($date);
      $now = time();
      $ago = $now - $time;
      if($ago < 60){
        $when = round($ago);
        $s = ($when == 1)?"second":"seconds";
        return "$when $s ago";
      }elseif($ago < 3600){
        $when = round($ago / 60);
        $m = ($when == 1)?"minute":"minutes";
        return "$when $m ago";
      }elseif($ago >= 3600 && $ago < 86400){
        $when = round($ago / 60 / 60);
        $h = ($when == 1)?"hour":"hours";
        return "$when $h ago";
      }elseif($ago >= 86400 && $ago < 2629743.83){
        $when = round($ago / 60 / 60 / 24);
        $d = ($when == 1)?"day":"days";
        return "$when $d ago";
      }elseif($ago >= 2629743.83 && $ago < 31556926){
        $when = round($ago / 60 / 60 / 24 / 30.4375);
        $m = ($when == 1)?"month":"months";
        return "$when $m ago";
      }else{
        $when = round($ago / 60 / 60 / 24 / 365);
        $y = ($when == 1)?"year":"years";
        return "$when $y ago";
      }
    }
    echo prettyDate("2012-07-22 12:23:45")."<br />";
    echo prettyDate("2010-11-12 22:25:45")."<br />";
    echo prettyDate("2012-01-01 01:00:00")."<br />";
    echo prettyDate("2001-05-30 00:00:00")."<br />";

希望本文所述对大家的php程序设计有所帮助。