What day was the official signing ceremony for the Declaration of Independence?

The official signing ceremony for the Declaration of Independence was on August 2, 1776, not July 4.

On July 4, Congress approved the final draft of the declaration, and John Hancock and the secretary of the Congress signed it.

But most members of Congress signed it at the official ceremony on August 2.

A few signed it later than that; one did not get around to it until 1781.