For now, there is no option to only edit the dates of the paycheck. You will need to delete them first. Then, recreate the paychecks using the correct dates. This article will provide you the steps on how to do that: Delete Or Void Paychecks.
In case they were sent to Direct Deposit, please take note that you need to delete them before they're processed. Cut-off time is before 5 PM PST, two banking days before the check dates.