Postmark

The exact calendar day, month, and year. Some postmarks include "AM" or "PM" indicators.

A postmark is an official postal marking applied by the United States Postal Service (USPS) to a mailpiece, such as a letter or package postmark

: USPS Postmark Rules Change: What You Need to Know by AARP explains how these shifts affect tax filings, Medicare documents, and mail-in ballots. The exact calendar day, month, and year

Before the mid-17th century, mail systems lacked accountability. Letters traveled slowly, and recipients had no way of knowing when a letter was sent or how long it had languished in transit. The exact calendar day