Hello, nannuge9. 

Yes, you'll want to go into the settings at the end of the month to change the closing date. Although, this isn't actually needed. It just secures your transactions and data prior to the closing date. I'll gladly provide the steps to help you set a closing date: 

1. Open the Company menu, click the Set Closing Date button.
2. Select Set Date/Password.
3. Enter a Closing Date and Closing Date Password.
4. Select OK to close the window.

The best part of manually setting a closing date is that you'll have ample of time to correct your books. Plus, you can also check your records to see if there are transactions that weren't record yet. 

A brief reference about the steps can be found here. 

Additionally, QuickBooks Desktop automatically creates an adjustment at the end of your fiscal year (not the closing date). A detailed explanation can be found in this article: Close your books in QuickBooks Desktop.

Need to reconcile your books before setting a closing date? A guide for the workflow can be found here. If there are other transactions you need to record or if you want to run a report, you can check other articles in this page. 

It's going to be a busy month ahead, so please let me know if there's anything else I can do for you. Here to offer guides and pointers to make your tax-related tasks easier.