The fastest and easiest way is to trigger the zap on a schedule, like 12:01am.

Then insert an AI step and ask it to output the sunrise and sunset today.

After that, add a Paths step with two paths set to always run. On path A, add a delay step to “delay until” the sunrise given by AI. On Path B, do the same but for sunset. 

Thank you!

Hi ​@GSK,
 
We just wanted to see how everything is going with your Zap. Did David’s recommendation get the job done? Feel free to reach out if you need further assistance with your Zap. We're glad to address any concerns and assist you.
 
We're looking forward to your response.

To trigger a Zap at sunrise or sunset, set the Zap to run daily (e.g., 12:01 AM). Use an AI step to fetch that day's sunrise/sunset times, then add a Paths step with two branches: one delays until sunrise, and the other delays until sunset. This way, your automation can run specific actions exactly at those times each day.