Screen Brightness Auto-Scheduler

WHAT IT DOES

Screen Brightness Auto-Scheduler is an accessibility tool that automatically adjusts your screen's effective brightness and color temperature throughout the day based on a customizable schedule. Unlike system-level brightness controls that affect your entire monitor, this script applies a CSS overlay filter directly to webpage content, allowing you to fine-tune brightness and warmth independently for day and night modes. A semi-transparent overlay with adjustable opacity reduces glare and eye strain during evening hours, while a sepia/warmth filter creates a more comfortable reading environment. The script intelligently transitions between day and night settings over a configurable period, preventing abrupt changes that can be jarring to the eyes. A compact floating indicator displays your current brightness percentage and the time remaining until the next scheduled change, keeping you informed without cluttering your workspace.

WHERE IT RUNS

This script operates as a userscript within the BotGentz extension on every webpage you visit across all websites and domains. It functions on any modern browser that supports the BotGentz extension, including Chrome, Firefox, Edge, Safari, and Opera. The script runs entirely client-side, applying CSS filters directly to the page's DOM without sending any data to external servers. It integrates seamlessly with existing page content, leaving the underlying webpage functional and interactive while applying visual adjustments.

HOW TO USE

After installation, the script automatically applies your default day and night brightness settings based on the configured sunrise and sunset times. Use the panel to set your preferred sunrise and sunset hours, then adjust day and night brightness levels using the sliders. The warmth slider controls the amount of sepia tone applied to the page, helping reduce blue light exposure during evening hours. The transition duration setting determines how smoothly the script shifts between day and night modes. Enable or disable the floating indicator to show your current brightness percentage and the time until the next scheduled change. Click the "Apply Settings" button to save your preferences and immediately update the current page. The indicator can be dragged to any position on your screen by clicking and holding it.

THE MECHANISM THAT MAKES IT WORK

Unlike browser extensions that request system-level brightness APIs, this script uses a dual-layer CSS overlay approach for maximum compatibility and precision. The first layer is a semi-transparent black overlay with adjustable opacity controlled by the brightness percentage, using the multiply blend mode to darken the page content without affecting the underlying layout. The second layer applies CSS backdrop-filter properties including sepia() and saturate(), creating warmth effects that simulate color temperature adjustments. The script calculates the actual brightness value by normalizing the user's setting against a logarithmic scale, ensuring that perceptual brightness changes feel smooth and gradual rather than linear. Transitions are implemented using requestAnimationFrame with delta-time interpolation, providing smooth 60fps animations during sunrise and sunset transitions. The time-to-change calculation uses JavaScript's Date object to compare the current time against the next sunrise or sunset, updating the indicator every 10 seconds without consuming significant system resources.

THE PANEL

The script panel is built using BotGentz's BGPanel framework and provides comprehensive control over brightness scheduling. The panel opens as a floating overlay that can be dragged anywhere on your screen, with a clean dark theme matching the aesthetic. It includes time selector dropdowns for sunrise and sunset hours, continuous sliders for day/night brightness and warmth settings, and a dropdown for transition duration. Toggle switches enable or disable the entire script and control the visibility of the floating indicator. A "Apply Settings" button saves all changes and immediately updates the current page, while a "Reset to Defaults" button restores factory settings. The panel collapses to a small icon when not in use and expands when clicked, remaining accessible but unobtrusive. Press the Escape key at any time to close the panel.

PLEASE NOTE

This script requires the free BotGentz extension to be installed and activated in your browser. The extension is available from the official BotGentz website. The script applies CSS overlays to the page, which may occasionally interfere with certain website elements such as video players or fullscreen content; you can temporarily disable the script via the panel toggle when needed. The brightness and warmth adjustments apply only to webpage content, not to browser UI elements or system-wide display settings. No data is collected, stored, or transmitted by this script; all settings are persisted locally using GM_setValue. If you experience performance issues on complex pages, you can disable the indicator or increase the update interval via the panel settings.