// CONTROLLER
class UserController extends Controller
{

    public function index()
    {
        $users = User::orderBy('created_at')->get()->groupBy(function($item) {
            return $item->created_at->format('Y-m-d');
        });

        return view('users', compact('users'));
    }

}

// NOTES
1. Function groupBy() is called AFTER the get(), it is a Collection function and not Eloquent.
If you do groupBy() before get(), it wouldn’t work, cause Eloquent groupBy() doesn’t accept callback parameter.
2. I’m doing group by formatted column $item->created_at->format(‘Y-m-d’), it will work only on created_at/updated_at column
that are automatically transformed to Carbon objects. If you want to group by other date/time fields, you should use Carbon,
like Carbon::createFromFormat(‘Y-m-d H:i:s’, $item->register_time)

// VIEW
<table class="table">
    @foreach ($users as $day => $users_list)
        <tr>
            <th colspan="3"
                style="background-color: #F7F7F7">{{ $day }}: {{ $users_list->count() }} users</th>
        </tr>
        @foreach ($users_list as $user)
            <tr>
                <td>{{ $user->name }}</td>
                <td>{{ $user->email }}</td>
                <td>{{ $user->created_at }}</td>
            </tr>
        @endforeach
    @endforeach
</table>

As you can see, we can still call $users_list->count() on the result, too. Pretty convenient.

So, that’s it. In short, you can do groupBy() with callback function, after getting all query results.