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

<?phpfunction 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。