Periodic execution of a program

[Tony Rems]

In article <1991Jan28.153105.2996 at mcs.drexel.edu> udparmet at mcs.drexel.edu (Daniel J. Parmet) writes:
>In article <5830 at rex.cs.tulane.edu> rawdon at rex.cs.tulane.edu (Michael Rawdon) writes:
>>
>>I was wondering if it would be possible to execute at recursively, that is,
>>have the file that at executes call at again to execute the same file at
>>the same time the next day.  I'm not sure if this would be possible.
>
>I haven't worked with crons in a while, but I believe that what you are trying
>to do should work.  When the runstream goes off, your file gets taken out of
>cron.  But you can simply have an at command in your run to put the file back
>into cron.  I'd be interested in finding out what happens, since my shell
>programming is a little rusty, and I may start up with it again soon.  Let me
>know.  Thanks.
>

Just about every man page I've seen for the at command has the following
in it:

   BUGS
        Due to the granularity of the execution of /usr/lib/atrun,
        there may be bugs in scheduling things almost exactly 24
        hours into the future.
   

This includes SunOS, Pyramid, Vax, and a number of others.  You 
may run into this problem.

-Tony