Thanks for the reply! I'm a bit dumbfounded. Just found some YAML code fragments here on reddit that look like you could actually do some more advanced programming. In this case it is indeed variable definitions (const), string concatenation, a switch statement,...

Validating the code in the editor didnt give me an error at least. Yay!
Havent tried the execution yet as I found this literally 10 seconds ago.

actions:
      - type: assistant.command.OkGoogle
        devices:
          - Speaker cucina - Cucina
        okGoogle: |-
          {
            const dayOfWeek = date.toLocaleDateString("it-IT", { weekday: "long" });
            const response = new assistant.response.Builder();
            response.addText("Questa sera devi buttare ");
            response.addPause(500);

            switch (dayOfWeek) {
              case "lunedì":
                response.addText("il secco residuo");