change shell script execution time

Kind of an embarrassing question to ask.

I have a server which runs under Debian 10.

It has 2 users: root and another one that I use for the application on the server.

There is a bash script that runs everyday under root. I need to change the time it runs.

I point out that it is a self made script that is located in the home directory of the application user.

Theres is nothing in root crontab or the user crontab. There is nothing in /etc/cron.daily or /etc/cron.d.

Is there anybody that have an idea how it might be implemented ?