Bug 511973 - Plasma Automatic Theme Switching from Day to Night is Too Late
Summary: Plasma Automatic Theme Switching from Day to Night is Too Late
Status: CONFIRMED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Day/night schedule (other bugs)
Version First Reported In: 6.5.1
Platform: Other Linux
: NOR wishlist
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-11-11 22:53 UTC by Wyatt Childers
Modified: 2025-12-26 15:09 UTC (History)
8 users (show)

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Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


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Description Wyatt Childers 2025-11-11 22:53:05 UTC
SUMMARY
The current way that the day/night cycle is implemented is a bit too slow. What I mean by that is that, it waits until sundown is complete rather than starting when sundown starts (or going somewhere in the middle).

STEPS TO REPRODUCE
1. Set Plasma to use an automatic day/night theme
2. Adjust the day/night cycle to your lat/log coordinates
3. Wait until evening

OBSERVED RESULT
- Plasma waits until the sun is completely set before switching themes.
- In the day/night cycle settings Plasma displays the time for the start of sunset (which is not the time it switches to the night theme).

EXPECTED RESULT
- Plasma waits until about half way through sunset to switch themes.
- In the day/night cycle settings Plasma displays the time it is going to switch themes.


SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-300.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 32 × AMD Ryzen 9 7950X 16-Core Processor
Memory: 64 GiB of RAM (61.9 GiB usable)
Graphics Processor 1: AMD Radeon RX 7900 XTX
Graphics Processor 2: AMD Ryzen 9 7950X 16-Core Processor
Manufacturer: ASUS

ADDITIONAL INFORMATION
This could potentially be resolved by adding options like "start at sunset, start after sunset, start X minutes before sunset." However, projecting my own use case ... I want the dark theme to be enabled so that Plasma isn't so hard on my eyes at night and so that it's easy to read in the daylight. So, about half way through sunrise and sunset seems like a more reasonable position to take.

My room was effectively near complete darkness even though the sun hadn't fully set and plasma (plus all of my apps waiting on the hint from Plasma) were still a very bright white.
Comment 1 Jeffrey Bouter 2025-11-21 20:50:48 UTC
I would like the default behavior to change as well, or at least to be able to change the behavior. I'd personally like the dark mode to kick in as soon as Night Light kicks in.
Comment 2 TraceyC 2025-11-26 23:14:57 UTC
This seems worth considering. I'm pretty sure this is behaving "as designed", so I'm categorizing this as wishlist (feature request).
Comment 3 John 2025-11-29 13:56:21 UTC
I noticed this problem too as was getting darker and darker outside and and the switch was still not happening.
From what I noticed over a few days, I think it was about 30 minutes too late.
I manually changed it to happen sooner, but it would be great if the automatic switch would be tweak a bit based on all our reports from all over the world until is good enough for everyone or most of the people.
Comment 4 Wyatt Childers 2025-11-30 22:28:01 UTC
(In reply to John from comment #3)
> I noticed this problem too as was getting darker and darker outside and and
> the switch was still not happening.
> From what I noticed over a few days, I think it was about 30 minutes too
> late.
> I manually changed it to happen sooner, but it would be great if the
> automatic switch would be tweak a bit based on all our reports from all over
> the world until is good enough for everyone or most of the people.

Yeah, that's basically what happened to me. For now I just changed my coordinates to manual and moved them an hour or so east to get it to trigger closer to when I need it.
Comment 5 John 2025-11-30 22:49:19 UTC
(In reply to Wyatt Childers from comment #4)
> (In reply to John from comment #3)
> > I noticed this problem too as was getting darker and darker outside and and
> > the switch was still not happening.
> > From what I noticed over a few days, I think it was about 30 minutes too
> > late.
> > I manually changed it to happen sooner, but it would be great if the
> > automatic switch would be tweak a bit based on all our reports from all over
> > the world until is good enough for everyone or most of the people.
> 
> Yeah, that's basically what happened to me. For now I just changed my
> coordinates to manual and moved them an hour or so east to get it to trigger
> closer to when I need it.

I don't remember how I did it, but what you did seems familiar and I thing I did the same, with blindly moving a bit east.
Comment 6 mikhailkrt 2025-12-07 16:55:19 UTC
It would be nice also to unbind the night light from the cycle. Right now, in the settings -> "Display & Monitor" -> "Night Light", it is not possible to manually adjust the time borders of the night light as before, there are "Always off", "Always on night light", "Sunrise and sunset".
Comment 7 TraceyC 2025-12-07 20:06:18 UTC
I'm curious why this was closed as not a bug?
Comment 8 Wyatt Childers 2025-12-07 20:37:52 UTC
(In reply to TraceyC from comment #7)
> I'm curious why this was closed as not a bug?

Looking at the emails it was an accident from mikhailkrt; changing it back to confirmed.
Comment 9 ic35734 2025-12-08 16:05:28 UTC
I support this, it has also been bothering me that the day/night theme switching is too late.

Configuring the day/night cycle based on manual geographic location works perfectly for Night Light, it gets the start and end times of sunrise and sunset perfectly, and automatically adjusts them throughout the year.

But the theme switching is not right - it switches from the light theme to the dark theme at the exact time when Night Light's transition finishes, so at the "end" time of sunset. For me, at this time, for at least half an hour it has already been too dark outside for light mode to be comfortable without switching on all of the artificial light sources.

I think it would be much more ideal for the KDE Desktop to switch the light theme to the dark theme at the beginning of sunset, at the time when the Night Light transition first starts. I think that's exactly how Apple's iOS on the iPhone behaves with its automatic light/dark mode switching in the "Sunset to Sunrise" setting. It switches at the beginning of sunset.

I hope this will be resolved soon. KDE's automatic light/dark theme switching was a feature that I have been looking forward to for many months, but this issue just makes it uncomfortable to use.
Thank you and best regards
Comment 10 ic35734 2025-12-26 15:09:44 UTC
Regarding my previous comment - my bad - it seems that iOS doesn't switch to the dark mode at the beginning of sunset, but right in the middle, between the beginning and end of sunset. I have no idea how it's handled by other GUI operating systems / desktop environments that have such a feature, but it's probably worth looking into it.