The line should read either:
0 0-23/2 * * * /home/username/test.sh
or
0 0,2,4,6,8,10,12,14,16,18,20,22 * * * /home/username/test.sh
Just do:
0 */2 * * * /home/username/test.sh
The 0 at the beginning means to run at the 0th minute. (If it were an *, the script would run every minute during every second hour.)
Don't forget, you can check syslog to see if it ever actually ran!
0 */1 * * * “At minute 0 past every hour.”
0 */2 * * * “At minute 0 past every 2nd hour.”
This is the proper way to set cronjobs for every hr.
To Enter into crontab :
crontab -e
write this into the file:
0 */2 * * * python/php/java yourfilepath
Example :0 */2 * * * python ec2-user/home/demo.py
and make sure you have keep one blank line after the last cron job in your crontab file
0 */2 * * *
The answer is from https://crontab.guru/every-2-hours. It is interesting.
Source: Stackoverflow.com