I understand how important it is to change the date of your transactions, lisa-arkbluetran. I'm here to help you with that.
Changing the period of the downloaded transactions is currently unavailable. QuickBooks Online automatically fetches the last 90 days of data during the online banking setup. If you want to get rid of them and only import the current ones, I'd suggest excluding them. Then, download and import the latest data to the program.
Here's how to exclude the transactions:
Go to the For Review tab.
Mark the box next to each transaction you want to exclude.
Select Exclude from the pop-up at the top.
Excluded transactions are moved to the Excluded tab and won’t be added to QuickBooks or be downloaded again.
After that, you can now manually import your downloaded data. Here's how:
From the Banking menu, click the Link Account drop-down.
Click on Upload from file from the options.
Press Browse and choose the file you want to upload.
Choose an account from the list, then Next.
Follow the on-screen instructions to map the fields.