In the terminal, I ran:
Then I added the following cronjob in the file
26 21 * * * /usr/bin/xbacklight -set 80
This was supposed to set the brightness to 80% at 9:26 PM. But its not working. I have tried this command in the terminal directly and it's working. Also, I added another cron job to open cheese at at a particular time and it's working fine. What should I do to fix this?