Add Link TopNavigationBar to a publishing site by powershell

Question

I have a site collection with some sites (Publishing theme).
I need to add some links to the top navigation bar and the quick launch by Powershell.

$web = Get-SPWeb "http://myurl"
$newLink = New-Object Microsoft.SharePoint.Navigation.SPNavigationNode -ArgumentList  @("test", "http://www.google.com");  
$web.Navigation.TopNavigationBar.AddAsLast($newLink);
$web.Update();

I tried this code,it runs fine, but I can not see the new link.
If I try to add a new link from the UI, I can not see it in the $web.Navigation.TopNavigationBar object.
It is working with an other template (ex team site)

Answer 1

Solved using the SharePoint 2013 Taxonomy.
These are the steps:
- Create a Term Set
- Setting site nav to use taxonomy

Tutorial: SharePoint 2013 Taxonomy

NB: I changed the Get-date format, this works for me $date = Get-Date -Format s