What is the dir structure of your <webapp>?
As a rule,
you should not keep your jsp files (in fact, any files that you want the user to access) anywhere under <webapps>/WEB-INF directory.
So, the first thing is, you need to fix the directory structure of your webapp. After that, in your jsp file, you can include another jsp file using:
<%@ include file="date.jsp" %>
This is assumming that the including jsp file and the included jsp file (date.jsp) are in the same directory. Usually, jsp files are kept under <webapp>/jsp directory.
If this all sounds confusing to you then you need to read about the directory structure of a webapp from any book (or even the specs explain it very good). This is very important for the exam.