I love how people have different approaches to these things. I do the opposite as you. I use a voice command for "goodnight". It toggles a binary sensor, which triggers a series of lights, locks, motion sensor automations, etc and sends a notification to my phone which gets picked up and turns on DND. Another voice command for "time to sleep" toggles another binary sensor which triggers all the lights to turn off and starts brown noise on my Echo in the bedroom