I just tested this and it worked. Set up a routine in Simple Commands by kloee to disarm ring. No other actions or any triggers. Create a routine in Alexa with a time scheduled and set the Simple Command routine in the Alexa routine as a “Scene”. My test worked just fine. I don’t personally have the need to arm/disarm Ring on a schedule but I was sure there was a way to do it. Actually, I might set up a routine to arm Ring in case I forget to do it at bedtime.
As a side note, Simple Commands by kloee has the ability to recognize when Ring is the “alarming” state and I use that trigger to activate all of my Tula smart plug controlled lights and auxiliary siren. If you do not define a trigger in SC routines, you can embed them into Alexa routines. If you define triggers, they will function autonomously and control any Alexa compatible devices. I find that S.C. by kloee adds a great deal of functionality to both Ring and Alexa