Running cron job on linux every 6 hours

Question

How can I run command every six hours every day? Tried this not working :

/6 * * * * *  mycommand

Answer 1

You forgot a * ,and you've too many fields, and it's the hour you need to care about

0 */6 * * * /path/to/mycommand

This means every 6th hour starting from 0, i.e. at hour 0, 6, 12 and 18 Which you could write as

0 0,6,12,18 * * * /path/to/mycommand

Answer 2

0 */6 * * *

crontab every 6 hours is a commonly used cron schedule.

Answer 3

Try:

0 */6 * * * command

. * has to

Answer 4

You should include a path to your command, since cron runs with an extensively cut-down environment. You won't have all the environment variables you have in your interactive shell session.

It's a good idea to specify an absolute path to your script/binary, or define PATH in the crontab itself. To help debug any issues I would also redirect stdout/err to a log file.

Answer 5

0 */6 * * * command

This will be the perfect way to say 6hrs a day.

Your command puts for 6 mins!