AUTO THEME

Powershell script which automatically switches .theme files depending on the time of day.

Description

This script automatically alternates between two .theme files chosen by the user, either via scheduled task or when run directly. As a scheduled task, it finds sunrise or sunset times by retriving location, or it stays offline using the hours indicated by the user.

The forgotten benefits of using .theme files

Many scripts and apps try to automate dark and light theme functionality under Windows 10/11, but they do so by modifying directly system registry settings. They then try to force a system refresh to show changes and in doing so incurr in many difficulties and potential compatibility problems for the user.

This script however directly starts .theme files as processes, therefore letting the system itself seamlessly operate the entire visual transition, be it just the application of dark mode, or with addition of visual styles, wallpapers and more.

In fact, using .theme files allows to set different wallpaper slideshows for each theme, while including other changes such as cursors, sounds, and more, all without forcing or tricking the system into unusual behavior.

All it takes are .theme files that the user has created, or that can be found ready-made in the system.

Installation

1. Create custom Light and Dark themes as preferred. To do so, simply modify settings in the Personalize window (including for example a wallpaper slideshow) and then save it as custom theme.

   

Alternatively, use any .theme file found by defualt in the system, or downloaded online. Notice that .theme files can always be directly modified in a simple text editor.

2. Open the file Config.ps1 and modify the following variables as preferred:

   

   • themeLight and themeDark should be the names of your custom .theme files.
   • LightPath and $DarPathshould be the paths to your custom .theme files. Usually Windows saves them in C:\Users\%username%\AppData\Local\Microsoft\Windows\Themes\.
   • $UseFixedHours should be set to $true if you want to use fixed hours for the theme change. If set to $false, the script will try to find the sunrise and sunset times for your location. When set to $true, the script will keep offline.
   • $LightThemeTime and $DarkThemeTime should be set to the hours when you want the theme to change. If $UseFixedHours is set to $true, the script will change the theme at these hours. If $UseFixedHours is set to $false, these variables will be ignored.
   • $UseUserLoc should be set to $true if the user provides the exact coordinates and timezone in the following variables. If set to $false, the script will try to find the location using System Location or the IP address.
   • $RandomFirst should be set to $true if you want the script to randomize the first wallpaper shown after the theme has been changed. Windows, in fact, even when shuffle=1is indicated in the .theme file, always starts with the first alphabetical image in the list. If this is set to $true, the user should provide the paths to the wallpaper slideshow folders in the following variables. These should be the same as indicated in the [Slideshow] section of the .theme file.

3. (optional) Run the script Setup.ps1 to create the main scheduled task. The script will ask for system privileges if not run as admin, and then proceed to create the "Auto Theme" task.

4. (alternative) You can of course create the task yourself using Task Scheduler, setting the triggers to anything you prefer. In this case, make sure that the Action is set up as follows:

   • Program/script: Powershell.exe
   • Add arguments: -WindowStyle Hidden -NonInteractive -ExecutionPolicy Bypass -NoProfile -File "C:\path\to\AutoTheme.ps1"
   • Run with highest privileges.

   

   

   

   It is advisable to always add the "On Workstation Unlock" trigger to the task. When the workstation is locked, the task may be unable to apply the theme fully, leaving out for example Slideshow customization and resulting in a hybrid "Custom" theme.

5. When triggered, the task will then run the script AutoTheme.ps1. The script itself will schedule the next temporary task ("Sunrise Theme" or "Sunset theme") to run at the next required theme change time, whether set by the user or identified through user location.

Usage

This script is designed to run from Task Scheduler, and after the initial setup doesn't need interaction from the user.

When run from terminal, however, using .\AutoTheme.ps1, the script will simply 'toggle' the theme (switching from one .theme file to the other) and then exit. This can be useful for testing purposes, but also for the odd times when we need to manually switch the theme regardless of task settings.

For convenience. you can create a shortcut to the script and place it on your desktop or taskbar for quick access. In this case, the shortcut should be to powershell.exe followed by the path to the script "C:\path\to\AutoTheme.ps1", indicating the same path in the Start in field: