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REDSHIFT(1)		    General Commands Manual		   REDSHIFT(1)

NAME
       redshift	- set color temperature	of display according to	time of	day

SYNOPSIS
       redshift	[-l LAT:LON | -l PROVIDER:OPTIONS] [-t DAY:NIGHT] [OPTIONS...]

DESCRIPTION
       redshift	adjusts	the color temperature of your screen according to your
       surroundings. This may help your	eyes hurt less or reduce the risk  for
       delayed	sleep phase syndrome if	you are	working	in front of the	screen
       at night.

       The color temperature is	set according to the position of  the  sun.  A
       different  color	 temperature  is  set during night and daytime.	During
       twilight	and early morning, the color temperature transitions  smoothly
       from  night  to	daytime	temperature to allow your eyes to slowly adapt
       over a period of	about an hour. At night	the color  temperature	should
       be set to match the lamps in your room. This is typically a low temper-
       ature at	around 3000K-4000K (default is 4500K).	During	the  day,  the
       color temperature should	match the light	from outside, typically	around
       5500K-6500K (default is 6500K). The light has a higher  temperature  on
       an overcast day.

       In  addition  to	 the  command-line tool	redshift, the GUI redshift-gtk
       provides	an alternative interface that shows up as a notification  icon
       in the desktop environment.

OPTIONS
       -h     Display help message.

       -v     Enable verbose output.

       -V     Show program version.

       -b DAY:NIGHT
	      Screen brightness	to apply (between 0.1 and 1.0).

       -c FILE
	      Load settings from specified configuration file.

       -g R:G:B
	      Additional gamma correction to apply.

       -l LAT:LON
	      Your  current location, in degrees, given	as floating point num-
	      bers, towards north and east, with negative numbers representing
	      south and	west, respectively.

       -l PROVIDER[:OPTIONS]
	      Select provider for automatic location updates (Use "-l list" to
	      see available providers).

       -m METHOD[:OPTIONS]
	      Method to	use to set color temperature (Use  "-m	list"  to  see
	      available	methods).

       -o     One-shot	mode  (do  not continuously adjust color temperature).
	      Use this with the	-P option to clear the	existing  gamma	 ramps
	      before applying the new color temperature.

       -O TEMP
	      One-shot manual mode (set	color temperature).  Use this with the
	      -P option	to clear the existing gamma ramps before applying  the
	      new color	temperature.

       -p     Print mode (only print parameters	and exit).

       -P     Reset existing gamma ramps before	applying new color effect.

       -x     Reset mode (remove adjustment from screen).

       -r     Disable fading between color temperatures.

       -t DAY:NIGHT
	      Color temperature	to set at daytime/night.

       The  neutral temperature	is 6500K. Using	this value will	not change the
       color temperature of the	display. Setting the color  temperature	 to  a
       value  higher than this results in more blue light, and setting a lower
       value will result in more red light.

       Default temperature values:

	      Daytime: 6500K, night: 4500K

CONFIGURATION FILE
       A configuration file with the  name  redshift.conf  can	optionally  be
       placed in ~/.config/. The file has standard INI format. General program
       options are placed under	the redshift header, while options  for	 loca-
       tion  providers	and  adjustment	methods	are placed under a header with
       the name	of that	provider or method. General options are:

       temp-day	= integer
	      Daytime temperature

       temp-night = integer
	      Night temperature

       fade = 0	or 1
	      Disable or enable	fading between color  temperatures  when  Red-
	      shift starts or stops

       brightness-day =	0.1-1.0
	      Screen brightness	at daytime

       brightness-night	= 0.1-1.0
	      Screen brightness	at night

       elevation-high =	decimal
	      The solar	elevation in degrees for the transition	to daytime

       elevation-low = decimal
	      The solar	elevation in degrees for the transition	to night

       dawn-time = HH:MM[-HH:MM]
	      The custom time interval for the transition from night to	day in
	      the morning.  When specified, the	solar elevation	 will  not  be
	      used  to determine the current daytime/night period. If this op-
	      tion is set, dusk-time must also be specified.

       dusk-time = HH:MM[-HH:MM]
	      The custom time interval for the transition from day to night in
	      the  evening.   When  specified, the solar elevation will	not be
	      used to determine	the current daytime/night period. If this  op-
	      tion is set, dawn-time must also be specified.

       gamma = R:G:B
	      Gamma adjustment to apply	(day and night)

       gamma-day = R:G:B
	      Gamma adjustment to apply	at daytime

       gamma-night = R:G:B
	      Gamma adjustment to apply	at night

       adjustment-method = name
	      Select  adjustment method. Options for the adjustment method can
	      be given under the configuration file heading of the same	name.

       location-provider = name
	      Select location provider.	Options	for the	location provider  can
	      be given under the configuration file heading of the same	name.

       Options	for  location providers	and adjustment methods can be found in
       the help	output of the providers	and methods.

EXAMPLE
       Example for Copenhagen, Denmark:

	      $	redshift -l 55.7:12.6 -t 5700:3600 -g 0.8 -m randr -v

       An example configuration	file with the same effect as the above command
       line:

	      [redshift]
	      temp-day=5700
	      temp-night=3600
	      gamma=0.8
	      adjustment-method=randr
	      location-provider=manual

	      [manual]
	      lat=55.7
	      lon=12.6

HOOKS
       Executables  (e.g.  scripts)  placed in folder ~/.config/redshift/hooks
       will be run when	a certain event	happens. The first  parameter  to  the
       script indicates	the event and further parameters may indicate more de-
       tails about the event. The event	period-changed is indicated  when  the
       period  changes	(night,	 daytime, transition). The second parameter is
       the old period and the third is the new period. The event is also  sig-
       naled when Redshift starts up with the old period set to	none. Any dot-
       files in	the folder are skipped.

       A simple	script to handle these events can be written like this:

	      #!/bin/sh
	      case $1 in
		  period-changed)
		      exec notify-send "Redshift" "Period changed to $3"
	      esac

AUTHOR
       redshift	was written by Jon Lund	Steffensen <jonlst@gmail.com>.

       Both redshift and this manual page are released under the  GNU  General
       Public License, version 3.

BUGS
       Please report bugs to <https://github.com/jonls/redshift/issues>

KNOWN ISSUES
       redshift	 will  not  affect the color of	your cursor when your graphics
       driver is configured to use hardware  cursors.  Some  graphics  drivers
       have an option to disable hardware cursors.

								   REDSHIFT(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION FILE | EXAMPLE | HOOKS | AUTHOR | BUGS | KNOWN ISSUES

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