I've got a couple of applications that I run on a scheduled basis (one, a reporting application, runs every hour during the working day, the other, a data harvesting application, runs in the middle of the night)
The first one I wrote quite a long time ago and it uses an 'autoexec' macro to run a bunch of queries, email some reports and shut itself down.
The second one I wrote after/while learning VBA, it uses a startup form, with some code in the OnLoad event, at the end of the code, it uses Docmd.Quit to shut itself down.
Both of them are scheduled using Win98 scheduler, as detailed above; the only problem I've ever had with them (since setting up, which was a bit fussy due to the command line fiddly bits) was when I used to run the regular one every twenty minutes; if our network was busy, the application wouldn't finish running it's queries (there are more than 50 of them (they all query different tables and couldn't be consolidated) and they are quite complex/slow) before the scheduler tried to launch it again, causing lock violations and the like, so I changed it to hourly running and no problems ever since.
One day I'm going to rewrite it in VBA, but not today.
It is possible to do without the scheduler idea and use a timer event in a form, but that requires the database to be open constantly, you would also need to do a bit of coding to avoid triggering a scheduled event more than once or not at all, whereas in (most of) the ready made task schedulers, it's all done for you andis usually pretty solid.
Mike