So you've installed Apple's macOS Mojave, you're fired up Dark Mode, you're admiring its sombre beauty. The next day, morning comes and that pretty desert photo you've put on as wallpaper has turned to day, but the UI (user interface) is still dark.

What gives? Well, Dark Mode does not change with sunrise and sunset. You have to enable or disable it manually.

This is the moment when you say:Wait. The Dynamic Desktop changes depending on time of day. Apple's Night Shift feature, both on iOS and macOS, can be set to change depending on time of day. But with Dark Mode you have to enable and disable manually?

Why, Apple? (this is the moment when you break down in tears).

No worries: A little app called NightOwl adds exactly this functionality to Mojave. It resides in your menu bar, it fires up on startup, and once you set it to change your desktop's appearance from Light to Dark and vice versa on sunrise/sunset, you can forget about it. You can also use it to quickly, manually switch from Light to Dark, or you can schedule it to switch between the two at any time of day or night.

While simple, the app is quite polished. When NightOwl does the switch, it lets out a cute owlish noise (which you can turn off in the settings). There's even a hidden feature: Right click on the icon in the menu bar to immediately toggle between Light and Dark mode.

The app, created by developer Benjamin Kramser, is free, but it's not open-source and hasn't been officially vetted by Apple, so install it at your own risk.

Or, if you're not in a hurry, Apple will probably add this feature itself in a year or two. Maybe three.

Hat/tip: Goran Peuc.