And in reading the page carefully, it appears that the second runs within the next minute; if that's so, then it can't be configured for every two seconds, except by setting up 30 separate cronjobs.[1] Note that while commands can be scheduled to run at any second, it is unlikely that they will be executed then but some time shortly thereafter, depending on the load on the system and the number of jobs that mcron has to start at the same time.