Hi Pooraccountant,
Welcome to the Community. QuickBooks Enterprise is designed to help you manage your accounting. The program offers a variety of tools and resources that help you streamline your business.
I can see the importance of being able to set up the AR Aging by month and I'll be happy to point you in the right direction. Since the ability to view the report in months isn't available, I encourage you to send feedback about this to our engineers. You can send feedback by clicking on the Help menu and looking for Send Feedback Online.
Here's a helpful article with more info about: Running an accounts receivable aging report.
In the meantime, feel free to ask other questions. I'll be one message away in case you need anything else.