How do I manually set location for redshift using the conf files?
I have geolocation turned off in Ubuntu 15.10. Is there a way to set location via GPS coordinates or neatest metro area using the in ~/.config/redshift.conf?
Yes, you can add the following to the config, where lat is your latitude and lon is your longitude. You can find these for example using google maps. Just right click anywhere on the map and choose "What's here?" from the menu.
[redshift]
location-provider=manual
[manual]
lat=48.1
lon=11.6
Additional info in this archwiki article.