If you want to Add Current Date and Time in your Power  Portal webpage follow the Below Steps:

Step 1:First you have to open Webpage–>Content page, On your Portal management app.

Step 2:Paste the below liquid Tag on Web page—>Content Page.

<h3> {{ now }} </h3>

Now save and sync configuration and reload the Portal  page. Now ,You can display current date time on your power portal web page.

It Look’s like the below page.

Hope this Helpful!