How do I make QB accept entries dated sooner than I originally started?

Good day, charles27.

I'll guide you through the steps on how you can add old transactions in QuickBooks Online. 

Old transactions can be manually recorded or recreated in the program. Just make sure to select the date when the transaction was created so they're posted and reported in the correct period. Here's how:

1. Click the + New icon in the upper-left hand corner.
2. Select a type of transaction. Choose between Invoice, Credit Memo, Estimate, Sales Receipt, or Refund Receipt for the customer side. Then, select Expense, Check, Bill, Pay Bills, Purchase Order, Vendor Credit, or Credit Memo if you're trying to record old vendor transactions.
3. Enter all other details such as payee, customer name, transaction dates, items o categories, and amount.
4. Click Save and close or Save and new.

Aside from that, you can also import old baking transactions using a CVS file. Use this article as a guide: Import bank transactions using Excel CSV files.

Depending on the type of subscription that you're using, there's also an option to import old invoices in some some of the QBO versions. Here's an article to get more details about this feature: Import multiple invoices at once.

Lastly, don't forget to run reports to check if all transactions have been imported. Open this article and use it as guide: Run reports in QuickBooks Online.

I'll be around if you need anything else.