Tasker (https://play.google.com/store/apps/details?id=net.dinglisch....) is perfect for this kind of thing. There is a learning curve but it's worth it - very powerful app.

and automateit, llama and even microsoft on x..

Try Twilight. Its reason for existence is to redshift and dim your screen in the evening hours so the excess blue light doesn't impact sleep quite so much, but if you don't like the red shift you can disable it and it'll just auto-dim.