Sorry, Wolfshade, you are wrong.
On Windows, you can execute a ".js" file from the command line.
And you can even pass along command line parameters and then read those in your JS code:
cscript updateSchedule.js "1/14/2013"
There's also a "wscript" that invokes the JS code in a more windowing environment, but I haven't seen much use for it.
You can also simply double click on a a ".js" file and have it automatically executed by the "cscript.exe" (which is part of the Windows Script Host -- WSH -- system).
And, finally, yes you can use the JS code to in turn invoke other executables, using the WshShell ActiveXObject.
Having said all the above, it seems likely that indeed Titanium could do this via JS (and, yes, you can use the Task Scheduler to invoke cscript and JS, of course--I do it all the time). But why?
You could just as easily invoke TestExecute
directly from the Task Scheduler. Unless the aim is to (for example only) randomly choose a different thing for TestExecute to do every 15 minutes, I don't see the need for JS to get involved here.