light/dark mode switch based key, on time or sunset/sunrise

[zacbowden]

An option inside Power Toys that automatically switches between Windows 10's light and dark theme at a certain time of day, or at sunset and sunrise, similar to how Night Light does in Windows 10. Feature could also be configurable so that the user can choose to have the automated process switch only app theme, or both app and system theme.

[crutkas]

We're prioritizing v1 work items but if a community member wants to help build this out, happy to dedicate time to this.

[niels9001]

Really like this idea! Here's a mock-up for the settings screen this feature would need to have.

XAML source (WinUI 3.0 Alpha) in this repo: https://github.com/niels9001/PowerToysUXWinUI3Alpha

[ismaelestalayo]

It’d also be very nice if we could choose two existing themes and set each one for day/night time (so not only the Light/Dark theme is changed, but also the wallpaper)

[niels9001]

Somebody referenced this project that does this: https://github.com/Armin2208/Windows-Auto-Night-Mode

[crutkas]

Cool project but that is GPL v3. We cannot use any source code from that project due to that license.

[alteredpark]

I do this in EventGhost using registry and cmd. Just chipping in case it helps.

Light:
REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize" /V AppsUseLightTheme /T REG_DWORD /D 1 /F

CMD: "%localappdata%\Microsoft\Windows\Themes\Day.theme"

Dark:
REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize" /V AppsUseLightTheme /T REG_DWORD /D 0 /F

CMD: "%localappdata%\Microsoft\Windows\Themes\Night.theme"

[crutkas]

Thanks @mikeparkie! Investigation is a massive part of the work!!!

[bradleybowman]

I also use the exact commands @mikeparkie referenced. I think I found them through a Google search, but I can confirm it works.

I use Task Scheduler; the action is 'Start a Program', command reg, with the argument set for light/dark theme. Granted, this is just a timed trigger.

One quirk I've noticed with this method: if you leave a File Explorer window open during the change, most of the Explorer UI honors the switch--the 'folder contents' portion of the window does not. It requires closing the File Explorer window and opening a new one to produce the expected result of a fully themed Explorer window.

Point is, it works, but it's not always elegant (not sure if it's possible to force reload the open windows entirely?)

[alteredpark]

@bradleybowman agreed, it's relatively crude in it's execution, but it works for the most part. And actually I didn't face any issues with the UI, other than the ribbon redraws first, followed by the rest of the frame/contents, take about 2 seconds in total. Enough to notice a transition.

If it's a content/icon refresh, then theres always the "ie4uinit.exe -show" command which should reload the icon cache (but I'm guessing a little there).

[BradleyBartlett]

Wrong @ in the comment