How to make a collection of two models grouped by date in Laravel 5.5?

I have two models Tour and Adventure. I want to make a group of both tours and adventures grouped by date. And display it like this:

July 17

Tour 1 Tour 2 Tour 3 Adventure 1 Adventure 2 Adventure 3

July 16

Tour 1 Tour 2 Tour 3 Adventure 1 Adventure 2 Adventure 3

I know how to make the grouping of a single model. It goes like this:

Tour::orderBy('created_at', 'desc')->take(20)->get()->groupBy(function($item)
          {
            return $item->created_at->format('d-M-y');
          });

How can I join the two models and display them into a single date? With the current code day appear in different collections.

via Chebli Mohamed