According to the Credit CARD Act, your due date must be on the same day each month (for instance, the 7th of each month).
In some rare cases, a card issuer may choose to change the payment due date because of business reasons. It’s quite common for issuers to allow cardholders to initiate the request for a change to the due date. However, some issuers do not allow such requests.
Consumers who change their due date typically do so because they find it easier to manage their finances. For instance, one might wish to schedule their due date around other due dates or the dates that they receive their paycheck.