请大神帮忙可能下为什么会报错 [ 新手入门 ]

Error 500
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 'UTC' for '8.0/no DST' instead

我访问自己新建的项目，就报错这个错，为什么？？我找了很久，不知道怎么回事，请大神帮忙看下，本人小白，最好说具体点啊