Your issue is not the date attribute, but the context of the page.
My educated guess is that you start with a dataview connected to the customers Entity. And connected this directly to navigation. A dataview will always display a single object of Customers. So the BIG question is which one?
And navigation is quite dumb, it can only open pages and kick microflows. And thus not able to pass an object.
To get more knowledge about this; https://gettingstarted.mendixcloud.com/link/module/5/lecture/65