Linux scheduled task crontab

I apologize first. I did not finish the essay yesterday. I made it up today.

Straight to question

The three files have been written at the same time. The scheduled tasks are completed below (if you are interested in other files, you can view relevant information on your own)

Crontab-l explanation: view the current scheduled task content

Crontab-e explanation: add the current scheduled task, press I to enter the writing mode, the operation is like vi

The written content is in the format of minute 0-59 hour 0-23 Date 1-31 Month 1-12 week 0-6 executed script address/Script Name

For example:

Press esc: wq! Save and exit

Linux scheduled backup, which has been cleared