php strtotime +1month的问题

我会带着你远行 2022-04-23 08:40 272阅读 0赞

### 文章目录 ###

*   *   *  场景
         *  参考资料

### 场景 ###

*  今天是2019-01-29, 利用redis写了一个定时器(标记本月是否已经发送过预警的邮件), 但是发现这个key的生存周期不对,
    
     *  `strtotime(date('Y-m-d', strtotime('+1 month')))` 这个到了2019-03-01，而期望的是2019-02-01

### 参考资料 ###

> [php.net strtotime ][php.net strtotime]关于+1month的解决方案

> > WARNING when using “next month”, “last month”, “+1 month”, “-1 month” or any combination of +/-X months. It will give non-intuitive results on Jan 30th and 31st.  
> > As described at : [http://derickrethans.nl/obtaining-the-next-month-in-php.html][http_derickrethans.nl_obtaining-the-next-month-in-php.html]
> 
> > $d = new DateTime( ‘2010-01-31’ );  
> > $d->modify( ‘next month’ );  
> > echo $d->format( ‘F’ ), “\\n”;
> 
> > In the above, using “next month” on January 31 will output “March” even though you might want it to output “February”. ("+1 month" will give the same result. “last month”, “-1 month” are similarly affected, but the results would be seen at beginning of March.)  
> > The way to get what people would generally be looking for when they say “next month” even on Jan 30 and Jan 31 is to use “first day of next month”:

$d = new DateTime( '2010-01-08' );
    $d->modify( 'first day of next month' );
    echo $d->format( 'F' ), "\n";?>```
    
    ### 解决
    
    + strtotime在1月30 31 29时使用next month +1month 得到的值是不直观的。 
    + 解决
    	+ first day of +1 month 代表第一天
    	+ last day of +1 month 代表最后一天

[php.net strtotime]: https://secure.php.net/manual/zh/function.strtotime.php
[http_derickrethans.nl_obtaining-the-next-month-in-php.html]: http://derickrethans.nl/obtaining-the-next-month-in-php.html