Final answer:
The approximate date a current address remains valid is known as the expiration date, signifying when the address information is no longer valid and requires an update.
Step-by-step explanation:
The approximate date through which a current address is valid is typically referred to as the expiration date. This is the date when the information or document that includes the address ceases to be valid and needs to be updated or renewed. It is not the effective date, which is when the information becomes valid; nor the renewal date, which is when an agreement or subscription is extended; nor the reference date, which might be any significant date relevant to the document or information.