WeatherCat Version 4.0.0 early dev release #4 is now available for testing. See https://athena.trixology.com/index.php?topic=3678.0 for more details and download.
It would be nice if WeatherCat had this feature built in
added to the todo list, provisionally slated for the 1.2 development
So, the way it works at the moment (if 'Disable Webcam Uploads At Night' is ticked) is the uploads (images/movies) are disabled approx. 45 minutes after sunset and re-enabled about 45 minutes before sunrise (so you don't miss the nice sunrise/sunset shots).
So although the image doesn't change, the overlay does?