The blog is a good place to get example code for this, however our time picker has changed since that blog post you linked to, you can see the newer version in this blog post.
Bascially you just add it to your control like this:
<mp:DatePickerControl ID="dpBeginDate" runat="server" ShowTime="True" SkinID="blog" CssClass="forminput">
Note that the tag mapping for <mp: needs to be in the <pages><controls> section of the Web.config file in your custom feature project like this:
<add tagPrefix="mp" namespace="mojoPortal.Web.Controls" assembly="mojoPortal.Web.Controls"/>
and you need a reference to the mojoPortal.Web.Controls project.
You don't need to include any script that is handled by the control. Note that it is designed to run in the context of mojoPortal not in a free standing separate web app. ie I assumme you are developing your custom feature according to our examples such that your code is in your own project and is copied up to the Web folder by a post build event so that it runs in the same web app as mojoPortal. See the Building a Guestbook Series of Videos to learn more about how to structure your project and solution.
Hope that helps,