one option is to use the QMSEDX and an external scheduler (windows scheduler)
another option is to use the Qlikview scheduler
schedule every month and, in the Qlikview document, check the month and raise an error when you want to skip that month
Do you want to reload a document in QV Desktop only? Then you can leave your PC on and use Windows Task Scheduler to create a schedule for reloading your document.
Do you have a QlikView server and no Publisher? Then check out Massimo's suggestions.
Do you have a QlikView Publisher at your disposal? I'll assume that you know how to use it; just create a task, add a Trigger "on a schedule" and select "Monthly". Then choose the months (and days) on which you want to reload your document.