Redshift adjusts the color temperature of your screen according to your surroundings. This may help your eyes hurt less if you are working in front of the screen at night. This program is inspired by f.lux (please see this post for the reason why I started this project).

 1 [redshift]
 2 temp-day=5700
 3 temp-night=2700
 4 gamma=0.8
 5 adjustment-method=randr
 6 location-provider=manual
 7
 8 [manual]
 9
10 ; lat=40.440811
11 ; lon=-8.43
12 lat=55.7
13 lon=12.6