bitday linux mint

#!/bin/bash
HOUR=`date +"%H"`

function set_bg {
  # export DBUS_SESSION_BUS_ADDRESS environment variable
  PID=$(pgrep -f cinnamon-session)
  export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
  gsettings set org.cinnamon.desktop.background picture-uri file:///tmp/bitday/$1

}

if [ "$HOUR" -gt 2 ] && [ "$HOUR" -le 5 ]; then
  set_bg "08-Late-Night.png"
elif [ "$HOUR" -gt 5 ] && [ "$HOUR" -le 9 ]; then
  set_bg "01-Morning.png"
elif [ "$HOUR" -gt 9 ] && [ "$HOUR" -le 12 ]; then
  set_bg "02-Late-Morning.png"
elif [ "$HOUR" -gt 12 ] && [ "$HOUR" -le 15 ]; then
  set_bg "03-Afternoon.png"
elif [ "$HOUR" -gt 15 ] && [ "$HOUR" -le 17 ]; then
  set_bg "04-Late-Afternoon.png"
elif [ "$HOUR" -gt 17 ] && [ "$HOUR" -le 19 ]; then
  set_bg "05-Evening.png"
elif [ "$HOUR" -gt 19 ] && [ "$HOUR" -le 23 ]; then
  set_bg "06-Late-Evening.png"
elif [ "$HOUR" -ge 0 ] && [ "$HOUR" -le 2 ]; then
  set_bg "07-Night.png"
fi