Merge pull request #531 from jonls/time-adjustment-docs

Add documentation for time-based adjustment

redshift.1

@@ -105,10 +105,20 @@ Screen brightness at daytime
 Screen brightness at night
 .TP
 \fBelevation-high\fR = decimal
-The solar elevation for the transition to daytime
+The solar elevation in degrees for the transition to daytime
 .TP
 \fBelevation-low\fR = decimal
-The solar elevation for the transition to night
+The solar elevation in degrees for the transition to night
+.TP
+\fBdawn-time\fR = 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 option is set, dusk-time must also be specified.
+.TP
+\fBdusk-time\fR = 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 option is set, dawn-time must also be specified.
 .TP
 \fBgamma\fR = R:G:B
 Gamma adjustment to apply (day and night)

redshift.conf.sample

@@ -9,6 +9,21 @@ temp-night=3500
 ; 1 will gradually apply the new screen temperature over a couple of seconds.
 fade=1
 
+; Solar elevation thresholds.
+; By default, Redshift will use the current elevation of the sun to determine
+; whether it is daytime, night or in transition (dawn/dusk). When the sun is
+; above the degrees specified with elevation-high it is considered daytime and
+; below elevation-low it is considered night.
+;elevation-high=3
+;elevation-low=-6
+
+; Custom dawn/dusk intervals.
+; Instead of using the solar elevation, the time intervals of dawn and dusk
+; can be specified manually. The times must be specified as HH:MM in 24-hour
+; format.
+;dawn-time=6:00-7:45
+;dusk-time=18:35-20:15
+
 ; Set the screen brightness. Default is 1.0.
 ;brightness=0.9
 ; It is also possible to use different settings for day and night