AWSのAmazon Linuxにcakephpをアップロードしたのですが、cakephpの初期画面が出ずに以下のようなエラーが出現しています。
AWSのサーバーにはphpをインストール済みです。
詳しい方、ご教示ください。よろしくお願いいたします。

Warning: strtotime(): 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 'UTC' for 'UTC/0.0/no DST' instead in /var/www/html/cakephp/lib/Cake/Cache/CacheEngine.php on line 60
Warning: _cake_core_ cache was unable to write 'cake_dev_ja' to File cache in /var/www/html/cakephp/lib/Cake/Cache/Cache.php on line 328
Warning: /var/www/html/cakephp/app/tmp/cache/persistent/ is not writable in /var/www/html/cakephp/lib/Cake/Cache/Engine/FileEngine.php on line 385
Fatal error: Uncaught exception 'CacheException' with message 'Cache engine "_cake_core_" is not properly configured.
         Ensure required extensions are installed, and credentials/permissions are correct' in /var/www/html/cakephp/lib/Cake/Cache/Cache.php:186
Stack trace:
#0 /var/www/html/cakephp/lib/Cake/Cache/Cache.php(151): Cache::_buildEngine('_cake_core_') 
#1 /var/www/html/cakephp/app/Config/core.php(374): Cache::config('_cake_core_', Array) 
#2 /var/www/html/cakephp/lib/Cake/Core/Configure.php(72): include('/var/www/html/c...') 
#3 /var/www/html/cakephp/lib/Cake/bootstrap.php(175): Configure::bootstrap(true) 
#4 /var/www/html/cakephp/app/webroot/index.php(104): include('/var/www/html/c...') 
#5 /var/www/html/cakephp/index.php(41): require('/var/www/html/c...') 
#6 {main} thrown in /var/www/html/cakephp/lib/Cake/Cache/Cache.php on line 186

追記：nginxを再起動したら、画面が出たのですが、CSSが効いていないようです。。