Running a cron job on Linux every six hours

Question

How can I run command every six hours every day? I tried the following, but it did not work: ``` /6 * * * * * mycommand ```

Accepted Answer

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

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

This means every sixth 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
```

Solution