How to block Workflow (whatsapp messages IA bot) at certain times?

I’m creating a workflow to respond to WhatsApp messages using an AI assistant.
However, I would like it to be activated or to respond only from 8 pm to 8 am daily.
I’m not able to do it using a “schedule trigger” and/or a n8n node to activate the workflow.

Does anyone have an idea of ​​how to do this?

Thanks!!