php还剩多长时间过期函数

还剩多长时间过期

public function TimeToSeconds( $end_time )
    {
        date_default_timezone_set('Asia/Shanghai');
        $now        = time();
        $expires_in = $end_time;
        $expires    = $expires_in - $now;
        if( $expires > 0 )
        {
            $seconds = (int)$expires;
            if( $seconds < 60 )
            {
                $format_time = gmstrftime('%S秒' , $seconds);
            }
            elseif( $seconds < 3600 )
            {
                $format_time = gmstrftime('%M分%S秒' , $seconds);
            }
            elseif( $seconds < 86400 )
            {
                $format_time = gmstrftime('%H时%M分%S秒' , $seconds);
            }
            else
            {
                $time        = explode(' ' , gmstrftime('%j %H %M %S' , $seconds));//Array ( [0] => 04 [1] => 14 [2] => 14 [3] => 35 )
                $format_time = ( $time[0] - 1 ) . '天' . $time[1] . '时' . $time[2] . '分' . $time[3] . '秒';
            }
            return ltrim($format_time,0);
        }
        else
        {
            return 0;
        }
    }