Field Description Allowed Value
MIN Minute field 0 to 59
HOUR Hour field 0 to 23
DOM Day of Month 1-31
MON Month field 1-12
DOW Day Of Week 0-6
CMD Command Any command to be executed.
crontab is available user wise, it is not available across the system, by default each user can create their own cron job
execute below command to create a cronjob
crontab -e #e stands for edit
this will open the crontab file, schedule your job accordingly
Below is the syntax
MIN HOUR DOM MON DOW <linux_command>
* * * * * echo "1" >> /tmp/file1 #this job will execute every minute and and add 1 to file1 everytime its executed
30 08 * * * echo "2" >> /tmp/file2 #this job will execute at 8.30 am every day and and add 2 to file2 everytime its executed
crontab -l #this will list all scheduled cron jobs