Bash script to manage Redshift with 5 different zones

bedshift.sh

#/bin/bash

#This bash file will run in a loop until killed, and edit the color temperature throughout the day based on the times below.

while true; do
        curTime=$(date +"%k")

        if (( $curTime >= 9 && $curTime < 18 )); then #between 9am and 6pm
                redshift -x #Reset all settings
        elif (( $curTime >= 18 && $curTime < 21 )); then
                redshift -O 4200k #Set color temp of 4200k
        elif (( $curTime >= 21 && $curTime < 23 )); then
                redshift -O 2300k #etc
        elif (( $curTime >= 23 || $curTime >= 0 && $curTime < 6 )); then
                redshift -O 1000k
        elif (( $curTime >= 6 && $curTime < 9 )); then
                redshift -O 2000k
        fi
        sleep 30

done

no transitions though, since oneshot mode doesn't seem to support that.