https://crontab.guru/#0_7-19_*_*_*
crontab myCrontabName
crontab -e (edit cronjob)
crontab -l (list cronjobs)
crontab -r (remove cronjob)
Example edit outside vim
crontab -l > file [ copy the crontab to a file ].
vi file [ make changes to the file as per your need ]
crontab file [ this makes the “file” as new crontab ]
Example file
MAIL=me@email.com
SHELL=/bin/tcsh
0 5 * * MON source /home/username/file.bat