Washington's Birthday is a United States federal holiday celebrated on the third Monday of February in honor of George Washington, the first President of the United States, who was born on February 22, 1732. It can occur on the 15th through the 21st of February inclusive.

Colloquially, it is now widely known as Presidents Day, a term deliberately coined to change the holiday into one honoring multiple presidents, and is often an occasion to remember all the presidents, not just George Washington. The day is also a state holiday in most states, with official names including Washington's Birthday, Presidents' Day, President's Day and Washington's and Lincoln's Birthday. Depending upon the specific law, the state holiday might officially celebrate Washington alone, Washington and Lincoln, or some other combination of U.S. presidents (such as Washington and the third president Thomas Jefferson, who was born in April).

From Wikipedia