State machines in games should be a lure enough for the kids: http://gameprogrammingpatterns.com/state.html

Scratch is actually pretty good at expressing state machines. Since all statements are atomic and all scripts on a sprite run in parallel, you can write one script that says

    forever:
      wait until Today == Saturday
      repeat until Today != Saturday:
        do things outside

and another script that says

    forever:
      wait until Today == Thursday
      repeat until Today != Thursday:
        if there is trash:
          take out the trash

and then any process that updates `Today` will cause the sprite to perform the right behavior on the right day.

I almost always use state machines.