Crontab - shell script will not start [Arch Linux]

Question

OS: Arch Linux

I have been trying to run a simple shell file using cron. The contents of the shell file is as follows:

#!/bin/sh
echo "Hello, world from a shell script!"
zenity --notification --text="Hello, world from zenity!"

Meanwhile, the contents of the crontab file is as follows:

#My custom backup
0 12 * * * /home/dave/myscripts/my_backup.sh

#Test
* * * * * /home/dave/myscripts/test.sh

The my_backup.sh file runs without any issues, but test.sh will not run at all. I own both files as user "dave"and both files are executable. Strange thing is: The my_backup.sh runs without any problems but the test.sh fails to run at all.

I have no idea where I am going wrong, please advise. David.

UPDATE (Monday, 31st January 2022)

Seems to be a display error as per this error message:

(zenity:23183): Gtk-WARNING **: 11:58:01.980: cannot open display:

Answer 1

UPDATE

After much searching I found the answer: Put the following into your crontab file:

export DISPLAY=:0 && zenity --info --text "This is a zenity crontab test." --width=250