F.lux is a free program that can adjust monitor color and brightness according to the lighting conditions around you. No need to install any extra hardware. It fetches data from the status of sun at your location. You need to set your zip code, or latitude and longitude to get the program to work properly.
After installing this software, click on the f.lux icon on the system tray. It pops up the settings panel. You can see the small circle inside it. This circle represents position of sun. It also displays the time of sunset at the top left. By default it is set to some other location so you need to click on the “Change settings” button at the top right to change the location. Click on “Change” button under “Set your location field”.
It will open a map in your default browser. Type your current location (name of your city and country) in the given box and click go. It will give you the latitude and longitude of your location.
Enter this lat and long in the box given. The tool is configured. There are sliders in the setting panel to adjust your lightning for day and night. Also, there is an option to set the transition speed. Set it to fast if you want to see the immediate change in screen brightness. This tool is effective as it manages to lower the screen brightness to a level that’s lower than the lowest level screen brightness you can set in Windows power option. Download F.lux to adjust monitor color and brightness automatically by the time of the day.