Unable to install drupal8.4
（1）drupal8.4.0在安装过程中一直在上方有显示：
Warning: DateTime::createFromFormat(): 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. in C:\myphp_www\PHPTutorial\WWW\drupal-8.4.0\vendor\symfony\http-foundation\Response.php on line 231
（2）安装到“需求评审”这一步时有以下警告：
发现警告
PHP OPCODE CACHING
未启用
PHP OPcode caching can improve your site's performance considerably. It is highly recommended to have OPcache installed on your server.
LIMITED DATE RANGE
Your PHP installation has a limited date range.
You are running on a system where PHP is compiled or limited to using 32-bit integers. This will limit the range of dates and timestamps to the years 1901-2038. Read about the limitations of 32-bit PHP.
（3）再继续安装就出现下面的错误页面，无法继续了。
安装 Drupal
错误信息Warning: DateTime::createFromFormat(): 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. in Symfony\Component\HttpFoundation\Response->__construct() (line 231 of vendor\symfony\http-foundation\Response.php).
Symfony\Component\HttpFoundation\Response->__construct('', 302, Array) (Line: 37)
Symfony\Component\HttpFoundation\RedirectResponse->__construct('http://www.d84.com/core/install.php?rewrite=ok&langcode=zh-hans&profile=standard&continue=1&id=1&op=start') (Line: 868)
batch_process(Object, Object) (Line: 619)
install_run_task(Array, Array) (Line: 540)
install_run_tasks(Array) (Line: 117)
install_drupal(Object) (Line: 44)
安装发生错误。
请继续到 错误页面
An AJAX HTTP error occurred.
HTTP Result Code: 200
Debugging information follows.
Path: /core/install.php?rewrite=ok&langcode=zh-hans&profile=standard&continue=1&id=1&op=do_nojs&op=do
StatusText: OK
ResponseText:
Warning: DateTime::createFromFormat(): 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. in C:\myphp_www\PHPTutorial\WWW\drupal-8.4.0\vendor\symfony\http-foundation\Response.php on line 231
{"status":true,"percentage":"7","message":"Completed 3 of 42.","label":"Installed \u003Cem class=\u0022placeholder\u0022\u003EField\u003C\/em\u003E module."}
