Hi there bill104,
Welcome to the QuickBooks Community! It sounds like you've been using the Receipt Capture feature in QuickBooks Online to enter and categorize your expenses. In order to ensure that your bookkeeping is as accurate as possible, entering correct dates is a vital step. Sometimes dates are entered incorrectly, but that's easy to fix. Let me explain.
Once you've added or matched the receipt as a bill or expense, you'll be able to locate that transaction by navigating to the Expenses tab. Once you've found it, simply click on it or select View/edit from the Action column. Using the appropriate field on the bill or expense, change the date to reflect the correct date as shown on the receipt. Then hit Save and close to save your changes.
If you'd like a refresher, here's a great article about the receipt capture feature: Capture and categorize expense receipts and bills in QuickBooks Online.
The process is really quite simple. Let me know if there's anything else I can assist with!