App: Dark Night
Developer: Hobbyist Software Limited
Genres: Utilities, Productivity

Dark and Light - made easy and automatic.
Run your AppleScript at sunrise and sunset (for example to switch dark mode)

Automatically switch between light and dark wallpapers based on sunrise and sunset, or on your own schedule.
Instantly see sunset and sunrise times.

You can also run your own Apple Script at sunrise and sunset. 
(The linked tutorial shows how you could write an AppleScript to toggle Dark Mode at sunrise and sunset.)

Easily switch with a single right-click on the menu icon

Release notes:
Updates the internals
Maintains the correct mode even if your computer was asleep at switchover time.