The date of her born is a little uncertain

Abigail Adams was born on November 11, 1744, according to numerous biographies. This is both true and false. Elizabeth and Congregationalist preacher Reverend William Smith welcomed their daughter into the world in Weymouth, Massachusetts when John Adams was nine years old. The Julian calendar was still in use at the time among British subjects in America. It was first used by Julius Caesar in 46 BCE, and it was standardized in all of Europe for more than 15 centuries. Unfortunately, his calendar was 11 minutes a year out of phase with the rotation of the planet. This might not appear to be a significant deal, but over time it did: The calendar was 10 days off track by 1582.

To solve this developing issue, Pope Gregory XIII unveiled a new calendar in 1582. Ten days of October were completely skipped at his instruction (October 4 was immediately followed by October 15), and steps were taken to reduce the frequency of leap years. The Gregorian calendar is still in use today.

However, Britain and her colonies didn't convert until 1752, while Catholic nations did so more or less immediately. The Julian calendar was then 11 days behind its original pace. Abigail Adams was therefore born on November 11, 1744, according this antiquated standard. While she was born on November 22, according to the Gregorian calendar is used now.