Bug 515533

Summary:	[Feature request] Option to set offset time for Day-Night Cycle
Product:	[Applications] systemsettings	Reporter:	kde.levitator555
Component:	kcm_nighttime	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	agurenko, kdedev, vlad.zahorodnii, walter.von.entferndt
Priority:	NOR
Version First Reported In:	6.5.5
Target Milestone:	---
Platform:	unspecified
OS:	All
See Also:	https://bugs.kde.org/show_bug.cgi?id=515558
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	patch to increase twilight duration after sunrise and before sunset, resp.

Description kde.levitator555 2026-02-05 03:58:50 UTC

SUMMARY
Currently, Day/Night Cycle tooling is only limited to dynamically changing the day/night theme based on Sunrise and Sunset time.
I would like an option to be able to switch to Day/Night theme based on -/+ minutes from the current Sunrise/Sunset time. 

A use case is that I would like to change to Night theme 30 minutes earlier than Sunset time. And I want to change to Day theme 1 hour after the Sunrise time.  I would like to avoid setting them manually in the custom times since the Sunrise and Sunset times are changing constantly throughout the year. 

An example is the Windows 3rd party app AutoDarkMode that has this exact option.

Comment 1 Walter von Entferndt 2026-02-05 16:47:39 UTC

Me too!

The request could also be called: "Adjust better for twilight in day-night cycle", and it also affects the smooth adjustment of display color temperature and optionally (the additionally feature request) to smoothly adjust the display brightness.

This is a reasonable feature request, since currently the start of changing the display color temperature is much too late at sunset and too early at sunrise.  You have to adjust better for the  twilight, which is short near the equator and long towards the poles, and the duration of twilight is longer in winter than in summer.

Related is my wish to optionally dim the display brightness at night by a configurable amount, default could be 70% of current daylight brightness (I go from 95% slowly to 65% in steps of 5% and back during sunrise).

Comment 2 TraceyC 2026-02-05 16:49:25 UTC

Thanks for the suggestion, I'll pass this along for consideration.

Related: bug 515558

Comment 3 Walter von Entferndt 2026-02-07 09:47:18 UTC

Created attachment 189322 [details]
patch to increase twilight duration after sunrise and before sunset, resp.

This is a simple solution to increase the twilight duration.
IMHO it matches (more or less) the durations proposed by the genuine bug reporter.
The patch increases the end of dawn (morning) after sunrise by the duration from civil dawn to sunrise, and decreases the start of dusk (evening) before sunset by the duration from sunset to civil dusk.
These values were plain (astronomical, IIUC) sunrise and sunset before, and do not fit human's perception of daylight, twilight and night.

Comment 4 Walter von Entferndt 2026-02-07 14:23:10 UTC

merge request is pending on invent.kde.org (GitLab)