How can I join 2 tables and sort them by date

Hi there, I don't really know how I can join two tables together in Laravel... Hopefully, someone can help here. So basically I have the regulars table and the commemoratives table. I would like all the items and show them by date. So now there are separate from each other, but how can I merge/join them together?

Controller:

  public function getAll(){
    $regulars = Regular::all();
    $commemoratives = Commemorative::all();

    return view('pages/all')->withRegulars($regulars)->withCommemoratives($commemoratives);
  }

blade:

  @foreach ($regulars as $regular)


  @endforeach


  @foreach ($commemoratives as $commemorative)


  @endforeach

Thanks!!