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All Add-ons

Add-on Time Theme Switcher
Time Theme Switcher

Switches between light and dark UI themes at scheduled times.
Add-on by CosmoMídias
About What's New Permissions Reviews Version History
16:11 o'clock: it's Light Theme now. 19:12 o'clock: now it's Dark Theme. 22:20: scheduled to change to Dark Theme.

Time Theme Switcher

Switch Blender between your favorite light and dark interface themes on a schedule. The add-on schedule a timer and applies your chosen presets automatically.

Features

  • 🌅 Time-based switching – configure independent light/dark activation times (default 07:00 and 19:00).
  • 🎨 Theme presets – pick any interface preset file (*.xml) already shipped with Blender or one of your own.
  • 🔁 Persistent timer – background timer ensures the correct theme is always active, even after reopening Blender. It also makes sure to re-eschedule whenever you adjust times.
  • 🧰 Safe fallbacks – the add-on gracefully handles invalid schedules and missing presets by reverting to Blender's stock themes.

Requirements

  • Blender 3.6.0 or newer (tested up to Blender 5.1)

Usage

  1. Open Edit → Preferences → Add-ons → Interface ▸ Time Theme Switcher.
  2. Check Time Theme Switcher to enable automatic switching.
  3. Pick the light and dark preset files via the menu buttons. The add-on scans Blender's preset directories, so stock files like Blender_Light.xml and Blender_Dark.xml appear automatically.
  4. Set the activation times (24-hour format).

Manual override

  • Use the preset menus to pick a different theme file at any time.
  • Click Refresh after drastically changing the system clock, so the timer recalculates immediately.

Scheduling Logic

  • The add-on converts each schedule into minutes since midnight and determines whether the current time lies in the "light" or "dark" window.
  • Default schedule: 07:00 light / 19:00 dark. These values are stored per-user and ship with sensible fallbacks.

License

This project is released under the GNU General Public License v3.0 or later. See the license file for the full text and your rights.


What's New

1.0.1 July 27th, 2026

Refactor: Improved mechanism of theme application on Blender startup.

See all versions


Permissions

This extension requests the following permission:

  • Files

    Read existing themes from disk

Developer
CosmoMídias
Rating
(4)
Version
1.0.1
Updated
1 h
Published
Nov. 14th, 2025
Downloads
1586
Size
19.5 KB
Compatibility
Blender 4.2 LTS and newer
Website
superhivemarket.com/creators/cosmomidias
Report Issues
gitlab.com/cosmomidias/time-theme-switcher/-/issues
License
GNU General Public License v3.0 or later
User Interface
...or download and Install from Disk
  • 19.5 KB

Reviews

See all
  • 3DDinosaur
  • v1.0.0
  • 11 h

Hi! I found an issue with Claude's hep, where the theme (light/dark) is not correctly reapplied when Blender is closed and reopened — even though load_post_handler is supposed to force a re-apply on load. The old theme colors stay in place until I manually click the "Refresh" button in the addon preferences, which does fix it immediately.

Looking at the code, I believe the problem is in apply_theme():

python try: with _context_temp_override(context_to_use, override): result = bpy.ops.script.execute_preset(...) except Exception: return False

bpy.ops.script.execute_preset is a UI operator and depends on a valid window/area/region context. During load_post (right at startup), the UI may not be fully ready yet, so this call can silently fail. Since the exception is caught with a bare except Exception: return False and nothing is logged, there's no way to know the apply failed.

This becomes worse combined with this check in apply_theme_for_current_time():

python if prefs.active_theme == desired_state and not force: return "skipped"

If active_theme was already set to the correct value from a previous session, and the startup apply silently fails, there's no automatic retry that would actually reapply the theme — since the timer's retry call doesn't use force=True, it just checks active_theme again and skips.

Suggestion: log the exception (e.g. print or self.report) instead of silently swallowing it, and/or don't trust active_theme as "already correct" until apply_theme() has actually returned True at least once in the current session. That would make it obvious when the startup apply fails and would let a proper retry happen.

  • CosmoMídias replied
  • 1 h

Thank you for reporting it. I've uploaded version 1.0.1 with the suggestion. Please check if it will work for you.

  • piereligio
  • v1.0.0
  • 2 mo

Working on Blender 3.5 as well :)

  • mamane-kabirou
  • v1.0.0
  • 8 mo

Thanks for this awesome addon! It was easy to set up.

I have a suggestion for a future update regarding multiple themes. It would be amazing to have:

I would really appreciate your help with thi

  • CosmoMídias replied
  • 7 mo

A multiple theme and multiple scheduler version in available from: https://cosmomidias.gumroad.com/l/time-theme-switcher-pro

4.5

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