time - PHP counts down to a certain time. There is an error. How to solve it? ? ?

<code><?php /**
 * Created by coder meng.
 * User: coder meng
 * Date: 2016/8/16 16:39
 */
$now=time();
echo '<br>';
$end=strtotime('2018-8-16 00:00:00');
$d=$end-$now;
$y=floor($d/3600/24/30/12);
$m=($d/3600/24/30)%12;
$dt=($d/3600/24)%30;
echo "距世界杯还有{$y}年{$m}个月{$dt}天";
</code>

There will be errors when writing year and month like this. How should I write it?
Does this error have any impact?

Reply content:

<code><?php /**
 * Created by coder meng.
 * User: coder meng
 * Date: 2016/8/16 16:39
 */
$now=time();
echo '<br>';
$end=strtotime('2018-8-16 00:00:00');
$d=$end-$now;
$y=floor($d/3600/24/30/12);
$m=($d/3600/24/30)%12;
$dt=($d/3600/24)%30;
echo "距世界杯还有{$y}年{$m}个月{$dt}天";
</code>

There will be errors when writing year and month like this. How should I write it?
Does this error have any impact?

Use DateTime to calculate the diff of two dates very conveniently and quickly.

<?php 

$datetime1 = new DateTime();
$datetime2 = new DateTime('2018-08-16');
$interval = $datetime1->diff($datetime2);
list($y, $m, $d) = explode('-', $interval->format('%Y-%m-%d'));

echo "距世界杯还有{$y}年{$m}个月{$d}天";

The key is that the logic is not clear. Is February 1st to March 1st one month or 28 (29) days?

A crooked method is to use the difference as date analysis and compare it with 1970-1-1

<?php

$now=time();
$end=strtotime('2018-8-16 00:00:00');
$d=$end-$now;

$y = date('Y', $d) - 1970;
$m = date('n', $d) - 1;
$d = date('j', $d) - 1;

printf('还有%d年%d月%d天', $y, $m, $d);

https://3v4l.org/1QEbC

Why use time()
Why not go to the early morning of the day?

<code>$y=floor($d/3600/24/30/12); //这个年有点牵强，有些月份不止30天呢。</code>

If your machine’s time error is not big, there shouldn’t be much error

<code>$dt=($d/3600/24)%30;

这句也有问题吧.</code>

For time, you can use Carbon, a third-party library, for quick calculations.