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: RESOLVED FIXED
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:
: 515558 (view as bug list)
Depends on:
Blocks:
 
Reported: 2025-11-11 22:53 UTC by Wyatt Childers
Modified: 2026-06-17 14:16 UTC (History)
16 users (show)

See Also:
Latest Commit: https://invent.kde.org/plasma/plasma-workspace/-/commit/4c4f4402e67cb982357bedb84c398e9371953139
Version Fixed/Implemented In: 6.7.0
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.
Comment 11 Gurenko Alex 2026-02-19 12:26:18 UTC 
*** Bug 515558 has been marked as a duplicate of this bug. ***
Comment 12 Giovanni Santini 2026-06-06 20:11:21 UTC 
Hi, I would like to know if progress is happening regarding this and otherwise if/how to contribute.

Since I live in Northern Europe, during summers and winters the delay in switching becomes very wide and frustrating to work with.
Comment 13 Vlad Zahorodnii 2026-06-08 10:55:41 UTC 
> Plasma waits until the sun is completely set before switching themes

Yeah, currently, transition times are synchronized to sunrise and civil dawn.

> Plasma waits until about half way through sunset to switch themes.

We can give it a try.
Comment 14 Bug Janitor Service 2026-06-08 11:27:25 UTC 
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/6697
Comment 15 Vlad Zahorodnii 2026-06-08 16:27:32 UTC 
Git commit 4eb568e99c0d5295437426ad890329ee1648f22e by Vlad Zahorodnii.
Committed on 08/06/2026 at 15:02.
Pushed by vladz into branch 'master'.

kcms/lookandfeel: Switch themes between civil dawn - sunrise and sunset - civil dusk

The global theme autoswitcher schedules the transition either at sunrise
or civil dusk, depending on time. One can argue that it's too late.

As a big of a compromise, this change makes the global theme transition
occur halfway between civil dawn and sunrise or sunset and civil dusk.

M  +17   -15   kcms/lookandfeel/kded/lookandfeelautoswitcher.cpp
M  +1    -2    kcms/lookandfeel/kded/lookandfeelautoswitcher.h

https://invent.kde.org/plasma/plasma-workspace/-/commit/4eb568e99c0d5295437426ad890329ee1648f22e
Comment 16 Vlad Zahorodnii 2026-06-08 18:51:19 UTC 
Git commit 4c4f4402e67cb982357bedb84c398e9371953139 by Vlad Zahorodnii.
Committed on 08/06/2026 at 16:30.
Pushed by vladz into branch 'Plasma/6.7'.

kcms/lookandfeel: Switch themes between civil dawn - sunrise and sunset - civil dusk

The global theme autoswitcher schedules the transition either at sunrise
or civil dusk, depending on time. One can argue that it's too late.

As a big of a compromise, this change makes the global theme transition
occur halfway between civil dawn and sunrise or sunset and civil dusk.


(cherry picked from commit 4eb568e99c0d5295437426ad890329ee1648f22e)

Co-authored-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>

M  +17   -15   kcms/lookandfeel/kded/lookandfeelautoswitcher.cpp
M  +1    -2    kcms/lookandfeel/kded/lookandfeelautoswitcher.h

https://invent.kde.org/plasma/plasma-workspace/-/commit/4c4f4402e67cb982357bedb84c398e9371953139
Comment 17 Bug Janitor Service 2026-06-17 05:51:33 UTC 
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/6765
Comment 18 Vlad Zahorodnii 2026-06-17 13:16:09 UTC 
Git commit 34cfbd588925922edcdf31bf32215d119e9b897b by Vlad Zahorodnii.
Committed on 17/06/2026 at 05:50.
Pushed by vladz into branch 'master'.

startplasma: Tweak the time when global themes are switched

Amends 4eb568e99c0d5295437426ad890329ee1648f22e.

M  +8    -9    startkde/startplasma.cpp

https://invent.kde.org/plasma/plasma-workspace/-/commit/34cfbd588925922edcdf31bf32215d119e9b897b
Comment 19 Bug Janitor Service 2026-06-17 13:16:57 UTC 
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/6767
Comment 20 Vlad Zahorodnii 2026-06-17 14:16:52 UTC 
Git commit f7b096ebf1e64adc7c3b7c0ff977baa0300cf1f1 by Vlad Zahorodnii.
Committed on 17/06/2026 at 13:16.
Pushed by vladz into branch 'Plasma/6.7'.

startplasma: Tweak the time when global themes are switched

Amends 4eb568e99c0d5295437426ad890329ee1648f22e.


(cherry picked from commit 34cfbd588925922edcdf31bf32215d119e9b897b)

Co-authored-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>

M  +8    -9    startkde/startplasma.cpp

https://invent.kde.org/plasma/plasma-workspace/-/commit/f7b096ebf1e64adc7c3b7c0ff977baa0300cf1f1