A bad night's sleep can affect your productivity like nothing else. And spending evenings in front of a bright computer screen does absolutely nothing to make you sleep better at night. The bright light emitted by the computer screen tricks your brain into thinking that it's still daytime -- not a good thing at 11 p.m. when your gray matter should be preparing itself for a good night's sleep.

Redshift and F.lux provide a simple fix for this problem. The utility adjusts the color temperature of the screen according to the time of the day at your specific geographical location. So as it's getting later (and darker) outside, the color temperature of your screen becomes warmer, making your brain (correctly) think that it's already evening.

Redshift is a command-line utility (although it does have a graphical front-end which can be installed separately), and its binary packages for popular Linux distros are available on the project's website. Users of Ubuntu-based distros will be pleased to learn that Redshift is also available in Ubuntu's official software repositories, so it can be installed using the sudo apt-get install redshift command. The utility accepts a handful of parameters, and you need to specify at least one: the latitude and longitude of your current location using the -l switch as in the example below ( you can use the Where Am I? page to quickly find your exact coordinates):

redshift -l 52.5:13.4

Usually this is enough to make Redshift do its job, but the utility sports other parameters you can tweak. Check the project's website for further info.

If you don't fancy Redshift, then you might want to give F.lux a try. A packaged version of the utility for Ubuntu is available in a separate PPA, and you can install F.lux on your machine using the following commands.

sudo add-apt-repository ppa:kilian/f.lux
sudo apt-get update
sudo apt-get install fluxgui

Once up and running, the utility adds an indicator applet. Click on it, and choose the Preferences item to configure the settings. All of the available options in the Preferences panel are self-explanatory, so you shouldn't have problems configuring F.lux.