What Can Display Dimmer Automate with Schedules and App Rules?

Display Dimmer can automate four things on Windows 10 and 11: brightness and contrast changes by time of day, per-app brightness settings, linked behavior across grouped displays, and (with Pro) color temperature for blue light filtering. Automation is the core of the paid tier — the free version covers everyday brightness and contrast control, while schedules, app rules, and unlimited temperature control sit behind a one-time Pro upgrade.

Time-based schedules

A schedule changes your display levels at set times rather than on demand. The site's own example is a dimming curve for the evening and a brighter level when your day starts, so the screen warms down as it gets dark and comes back up in the morning without you touching a slider.

What this means in practice:

• You define the times and the target levels once; the app applies them going forward.
• Schedules are the mechanism behind the "set it once, let Display Dimmer handle the rest" framing on the site.
• Because schedules run on time rather than on a trigger, they suit fixed routines — a workday start, an evening wind-down — better than irregular use.

App rules

App rules apply your preferred settings to specific applications. When you switch to an app you've configured, Display Dimmer applies that app's brightness (and, with Pro, temperature) instead of leaving whatever the previous app or schedule set.

This is the feature to reach for when one program needs different levels than everything else — for example, a photo editor where you want neutral, full brightness, next to a reading app you keep dimmer. The site describes app rules as "your preferred settings for the apps you use," and shows a settings screen combining a display control, a schedule, and an app rule.

Linked displays

If you run more than one monitor, linked displays keep grouped screens and their automation working together. Grouped displays move as a unit, so a schedule or rule that fires applies across the group rather than to one screen at a time.

This matters most when your monitors are mismatched — different panels often need different raw values to look equally bright. Grouping lets the automation treat them as one target instead of you tuning each separately.

Color temperature and blue light filtering (Pro)

Temperature control shifts the screen warmer, from neutral 6,500 K down to 2,500 K. The free tier includes 30 minutes per day of temperature control; Pro removes that limit. Because temperature is part of the same automation system, it can be scheduled — the site's example is a warmer evening setting — and applied per app through app rules.

If blue light filtering is the reason you're looking at the app, the automation angle is the useful part: instead of remembering to warm the screen at night, a schedule does it, and app rules keep it from fighting with apps where you need accurate color.

What automation does not cover

Automation controls brightness, contrast, and (Pro) temperature. It does not change how the app talks to your hardware. Display Dimmer uses DDC/CI to adjust a monitor's own brightness when the display and connection support it, and falls back to software dimming (gamma-based) when they don't. The app tracks DDC/CI results per display and, after repeated failures, can pause hardware control for that display and switch to software dimming.

That fallback is worth knowing before you build a schedule around a particular monitor: a display that drops to software dimming may not respond the same way as one on hardware control, and the app handles that per display rather than globally.

Choosing between free and Pro for automation

The site's own summary is "control brightness and contrast for free" and "upgrade once for unlimited temperature control, more automation, and advanced tools." So if schedules, app rules, or linked displays are what you're after, those are Pro features. Pricing is a one-time upgrade with no subscription; the exact amount isn't stated in the material available here, so check the purchase page before deciding.

A Mac version is in beta and has a free waitlist if you're not on Windows.