What about add function to set light and dark themes and switch them on system theme changes?
Like in IINA

When system theme changes, then changes theme in app.

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:
For anyone that doesn't want to wait, I made a little extension that does this for you:
https://marketplace.visualstudio.com/items?itemName=LinusU.auto-dark-mode
You can set the dark and light mode in the settings:

Hope this helps someone!
Someone can confirm but I think this was in the last release?
@Lapsusone I think that the only thing that was in the last release was that the window borders and system dialogues will now follow the system dark theme settings. It still doesn't have a mechanism for automatically switching the editor theme...
@LinusU, thanks for extension, it works!
@LinusU So thank you!
@bpasero what about add built in support of that feature?
I would also like this, but I can see this getting complicated with themes that provide multiple light/dark themes. Here is what GitHub Desktop does this:

I'd love to see this built-in. I've been using @LinusU's extension (https://marketplace.visualstudio.com/itemdetails?itemName=LinusU.auto-dark-mode) which works well most of the time but sometimes does not pick up the change.
Anyhow, I think it makes sense for this to be in the core.
As I wasn't completely satisfied with @LinusU's extension, there's now another extension for this task:
ThemeSwitch on VS Code Marketplace
It is customizable and can therefore switch between more than 2 themes. You can choose any time of day and combine that time with the theme you prefer at that time.
Thanks for creating this issue! We figured it's covering the same as another one we already have. Thus, we closed this one as a duplicate. You can search for existing issues here. See also our issue reporting guidelines.
Happy Coding!
Most helpful comment
For anyone that doesn't want to wait, I made a little extension that does this for you:
https://marketplace.visualstudio.com/items?itemName=LinusU.auto-dark-mode
You can set the dark and light mode in the settings:
Hope this helps someone!