How do we use this module?

Just add any date filter, for example "authored on" for node

+1.

After adding Authored on as a filter, there no changes to the interface. I am not able to realize step #7 in the Configuration section of the Read me, the date field filter added above now allows to select date from the Datepicker calender instead of the default input field provided by core.

+2. I also want to use this for an authored on filter and can't see any way to do that in the UI, either with views basic exposed filters or better exposed filters.

+1

I was also under the impression this module was not doing anything as well.

As it turned out, I had the date_popup module enabled and it "wins" over the date_filter module so it is always used for exposed date views filter.

I was able to identify the conflict with this drush command :

drush php-eval "var_export(\Drupal::service('plugin.manager.views.filter')->getDefinition('date'))";

array (
  'plugin_type' => 'filter',
  'id' => 'date',
  'class' => 'Drupal\\date_popup\\DatePopup',
  'provider' => 'views',
)

After disabling the date_popup module, date_filter was able to do its job properly!

Maybe my experience can help someone else landing here like I did...

Thanks for this great module!