(CNN) -- Here's a look at what you need to know about Washington's Birthday, also called Presidents' Day, a federal holiday marked on the third Monday in February. In 2014, Washington's Birthday will be celebrated on February 17th.
Facts: The official federal holiday on the third Monday in February is called "Washington's Birthday."
People started calling it Presidents' Day later, to honor Abraham Lincoln and other presidents.
Timeline: February 1732 - George Washington is born. The Julian "old style" calendar, which was used at the time, marks his birth date as February 11.
1752 - The Gregorian "new style" calendar is adopted, putting Washington's birthday on February 22.
1789-1797 - Washington's birthday is celebrated on both days while he is president.
February 12, 1809 - Abraham Lincoln is born.
1861-1865 - Abraham Lincoln is president.
1885 - February 22 is designated as a federal holiday to honor Washington's birthday.
1968 - Congress passes the Monday Holidays Act. Existing federal holidays will now be observed on Mondays, to give government workers three day weekends. After much debate, Congress rejects combining Washington's and Lincoln's into one Monday called "Presidents' Day." The bill goes into effect in 1971.
February 18, 2000 - President Bill Clinton mistakenly refers to the official federal holiday "Washington's Birthday" as "Presidents' Day" in a proclamation.