Script I wrote to change my system theme automatically throughout the day.

switcher.py

#!/bin/python
import datetime as dt
import time
import os

SUNSET  = 20 # switch to dark mode at 8PM
SUNRISE = 6  # day starts at 6AM

DAY_WP   = "/home/ant/Pictures/wallpapers/day"
NIGHT_WP = "/home/ant/Pictures/wallpapers/night"

# DAY_THEME   = "Pop"
DAY_THEME   = "Materia-light-compact"
NIGHT_THEME = "Pop-dark"

DAY_KITTY   = "/home/ant/.config/kitty/Github.conf"
NIGHT_KITTY = "/home/ant/.config/kitty/Jellybeans.conf"

WALLPAPER_COMMAND = "gsettings set org.gnome.desktop.background picture-uri {}"
THEME_COMMAND     = "gsettings set org.gnome.desktop.interface gtk-theme {}"
KITTY_COMMAND     = "rm /home/ant/.config/kitty/theme.conf; ln -s {} /home/ant/.config/kitty/theme.conf; kitty @ set-colors -a {}"

if __name__ == '__main__':
    while (True):
        wallpaper = ""
        theme     = ""
        kitty     = ""

        now = dt.datetime.now()
        if now.hour >= SUNSET or now.hour < SUNRISE: 
            wallpaper = NIGHT_WP
            theme     = NIGHT_THEME
            kitty     = NIGHT_KITTY
        else:
            wallpaper = DAY_WP
            theme     = DAY_THEME
            kitty     = DAY_KITTY

        os.system(WALLPAPER_COMMAND.format(wallpaper))
        os.system(THEME_COMMAND.format(theme))
        os.system(KITTY_COMMAND.format(kitty, kitty))

        time.sleep(1 * 60) # check every minute