Is there any way to create a custom time period that only uses Sunset or Sunrise and not both?

Excellent. If it’s the Aeotec hub, that’s the most recent one. So in that case, you can use an edge driver to create virtual switches that will run locally on your hub.

There are several popular ones created by the community, each with slightly different features. You can find all of them on the quick browse lists in the community- created wiki. Look for the list for “virtual devices.”

In all cases, you will follow a link that the author gives you, subscribe to that author’s channel, choose the edge driver you want to download to your own hub, and then wait.

It can take as much as 12 hours before it gets downloaded, but usually it’s quicker than that.

Once it is downloaded, then you can get to it through the app. The different drivers do have somewhat different instructions, so ask any further questions in the author thread for the driver you are going to use.

https://thingsthataresmart.wiki/index.php?title=Quick_Browse_Lists_for_Edge_Drivers

For the purpose as described in this thread of just creating a single virtual switch, I’d suggest starting with the following: