A bug introduced in the March Pixel Feature Drop broke the "sunset to sunrise" dark theme scheduling on Pixel devices.

For example, I don’t like to use Dark mode as it decreases the readability for me. So it depends on your personal choice. To make Windows 11 change the theme automatically, you need to use a ...

For two updates in a row now, automatic dark theme that uses sunrise and sunset is still broken for Google Pixel owners.

Now you can switch from System default to Light or Dark mode theme on Edge browser ... Apart from this, you can also choose a predefined theme or use a color scheme using the Page colors feature.

On iPhones, you will need iOS 13 otherwise you’re out of luck. Prior to the dark theme, the best you could do was use a dark wallpaper to reduce the strain on your eyes at 3 am in the night.