How do I change the date on a whole month of expenses?

Hi info-planborgani,

Welcome to the Community! QuickBooks Online makes managing your business flexible and simple. It's important that your transactions are recorded correctly to ensure that your books stay in order, I can explain how to edit the date if an expense. 

To change the dates, need to edit the date on each expense manually, as there isn't a way to batch edit the dates. To edit an expense in QuickBooks Online, navigate to the Expenses menu. Once you locate one of the expenses you want to edit, click the View/Edit button. Update the date as needed, then select Save and close. You can find more details about entering and editing expenses in this Community article: Enter and manage expenses in QuickBooks Online

Please let me know if I can answer any other questions! 

@info-planborgani 

As another option, you may export the transactions out to XLS, modify the dates, and reimport back into your account.

https://transactionpro.grsm.io/qbo