I realy like the PHPStorm extension ChronoMorph which switches between light and dark themes depending on the time of day.
I wanted that for my terminal too. And since the kitty terminal can be remote controlled, we can implement this with two simple scripts.
One script fetches the sunrise and sunset times. It can run once a day.
The other one checks the current time against the sunrise and sunset times and determines if a light or dark mode should be used. It can run every five minutes or however often you like.