Crontab is one of the useful commands for scheduling repetitive jobs in Red Hat Linux.
OS: RHEL 7.9
Job: To run echo hiya command at 14:23 every day in user marco
Step 1: crontab -u marco -e
Step 2: insert 23 14 * * * /bin/echo hiya
(23, 14, *, *, * stand for minutes, hours, day of month, month, day of week)
You can browse the website below for understanding cron schedule:
https://crontab.guru/#23_14_*_*_*
Finally, using command (crontab -l -u marco) to check the job whether it is running.
#crontab