Change the wallpaper according to the time of the day. (KDE only)

change_wallpaper.sh

#!/usr/bin/env bash

time=$(date +%H | numfmt)
night=true

day_wallpaper="/path/to/image"
night_wallpaper="/path/to/image"

if [[ "$time" -ge 6 ]] && [[ "$time" -lt 17 ]]; then
	night=false
fi

if [[ "$night" = true ]]; then
	plasma-apply-wallpaperimage "$night_wallpaper"
else
	plasma-apply-wallpaperimage "$day_wallpaper"
fi