CRON what is correct time code for every 6 hours?

Question

I just want to know which one should work just fine for Run every 6 hours forever:

0   */6 *   *   *

or

*   */6 *   *   *

Thanks

Answer 1

I would say the first one. It will run once every six hours. You can also try to set specific hours like this:

00 2,8,14,20 * * * 

You might also find useful to check out this page.

Answer 2

The second... Which you could have realised for yourself by consulting the appropriate manpage.