function tranTime($time) { 
$rtime = date("m-d H:i",$time);  
$htime = date("H:i",$time);  
$time = time() - $time;  
if ($time < 60) {  
$str = '刚刚';  
} elseif ($time < 60 * 60)  {  
$min = floor($time/60);  
$str = $min.'分钟前';  
} elseif ($time < 60 * 60 * 24){  
$h = floor($time/(60*60));  
$str = $h.'小时前 '.$htime;  
} elseif ($time < 60 * 60 * 24 * 3) {  
$d = floor($time/(60*60*24)); 
if($d==1){ 
$str = '昨天 '.$rtime;  
} else { $str = '前天 '.$rtime;}  
} else {  
$str = $rtime;  
}  
return $str;  
}  
//函数tranTime()中的参数$time必须为Unix时间戳，如果不是请先用strtotime()将其转换成Unix时间戳 
//调用，调用函数，直接输出： 
echo tranTime($time);