I have set up cron jobs using the following command
It seems that if a cron job is scheduled to run within the same day (i.e. computer has not been rebooted), then the cron job runs OK. However, if a cron job is scheduled to run several days later (i.e. computer has been rebooted at least once), then the cron job would be missed.
Moreover, every time when I use "crontab -e" to edit the crontab file in the "nano" editor, the top line shows that I am editing a different file, e.g.
File : /tmp/crontab.PLwi9Z/crontab File : /tmp/crontab.degfpN/crontab File : /tmp/crontab.odqbkT/crontab
I want to know that is this normal for crontab and how to schedule a job to run several days later (i.e. after several reboots). I am using an Ubuntu 12.04 amd64 system.
Thanks for any suggestion.