NOTE: crontab
In MacOS, we have crontab and periodic can pick, but I didn't find how to set a certain time like 3 pm to run the periodic. Thus, I switch to crontab and it's very easy to use, you can type the command:
crontab -e
Or you like to run commands as root:
sudo crontab -e
Then modify in the editor(usually is vim) like the following format:
#+beginsrc crontab
1. * * * * racket fetch.rkt >/tmp/stdout.log 2>/tmp/stderr.log
#+endsrc
1.1. Online Tool: crontab.guru
Each line like the above code is a command, * * * * * points out when
to run it. It is hard to remember the semantic of the format
* * * * *, but thanks god we have https://crontab.guru/.
Finally, you can change log file to anywhere you like, that's all you need to know. Have a nice day.