Using @reboot @monthly @weekly.... in CRON

The following keywords are available, which can be substituted for the normal five field used under cron

    String         What it means
       
    @reboot        Run once, at startup.
    @yearly        Run once a year, "0 0 1 1 *".
    @annually      (same as @yearly)
    @monthly       Run once a month, "0 0 1 * *".
    @weekly        Run once a week, "0 0 * * 0".
    @daily         Run once a day, "0 0 * * *".
    @midnight      (same as @daily)
    @hourly        Run once an hour, "0 * * * *".

@reboot can be used a start a program on reboot.
Another possible use, could be to trigger a email notification/alert whenever a reboot is taken on
the given machine.