While we do provide modus-themes-toggle to manually switch between the
themes, users may also set up their system to perform such a task
automatically at sunrise and sunset.
This can be accomplished by specifying the coordinates of one’s location using the built-in solar.el and then configuring the ‘circadian’ package:
(use-package solar ; built-in
:config
(setq calendar-latitude 35.17
calendar-longitude 33.36))
(use-package circadian ; you need to install this
:ensure
:after solar
:config
(setq circadian-themes '((:sunrise . modus-operandi)
(:sunset . modus-vivendi)))
(circadian-setup))