Welcome to the Community, @sarah116.
In QuickBooks Online (QBO), the option to change the date of transactions in the Banking screen/page is currently unavailable.
The system will only depend on the information downloaded from your Financial Institution (FI). You can only filter the dates of the specific transactions you want to see by clicking the All dates drop-down.
If you want to know more about managing bank transactions in QBO, please check out this article: Categorize and match online bank transactions.
Let me know if you're referring to something else or if you have any other questions in the comment section below. I'll be more than willing to assist. Have a good one!