Hi Steven_C,
Thank you for submitting a support ticket! Our team will be in touch soon. Generally, the bank feed system looks at the amount of the bank feed transaction to match the transaction in the file. If the amounts match, then bingo! The two transactions can be paired together. In your case, if you want the date to be the same as the bank feed date, you don't need to create a new transaction. Instead, just tweak the date from the existing transaction in MYOB. This way, you won't end up with duplicate transactions. Since you have already created a new transaction, I suggest going to Banking >> Find transactions to delete the transaction. Then, you can edit the date of the original transactions to match them with the bank feed.
Feel free to get in touch if you need more help.
Cheers,
Princess