Warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use

运行php文件报错如下：

Warning: date(): It is not safe to rely on the system's timezone settings. 
You are *required* to use the date.timezone setting or the date_default_timezone_set() function. 
In case you used any of those methods and you are still getting this warning, you most likely misspelled 
the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select
 your timezone.

解决办法：

方法1： （最好的方法）在php.ini里加上找到date.timezone项，去掉前面的";"，添加设置date.timezone = "Asia/Shanghai"，北京的时间也写成上海那个。

重启环境，然后出现如下问题：

Warning: date(): Invalid date.timezone value 'Asia/Beijing', we selected the timezone 'UTC' for now. in D:\Tomcat\apache-tomcat-7.0.77\webapps\webOne\qshxxkj\WEB-INF\php-bin\Wxpay\example\h5.php on line 16 在php.ini中date.timezone = "Asia/Shanghai",加上如下这句话即可： date_default_timezone_set('UTC');

重启服务即可。

方法2： 在需要用到这些时间函数的时候，在页面添加date_default_timezone_set("PRC");

方法3： 在页头加上设置时区ini_set('date.timezone','Asia/Shanghai');