Cronjob based on system time or its own time elapse Cronjob is based on the system time or its own time elapse? If it is system time, when I change the system time manually, will cronjob follow the new set up time accordingly?

`cron` uses the system clock, which it checks every minute. For changes to the system clock, the following extract from the `man` page might be useful:

> Special considerations exist when the clock is changed by less than 3 hours, for example at the beginning and end of daylight savings time. If the time has moved forwards, those jobs which would have run in the time that was skipped will be run soon after the change. Conversely, if the time has moved backwards by less than 3 hours, those jobs that fall into the repeated time will not be re-run.