When Washington was born on Pope Creeks Farm in Westmoreland County, Virginia, it was February 11, 1731! This can be blamed on another inaccurate calendar, the Julian Calendar, which was still used by the British Empire until 1752. Although the Gregorian Calendar was utilized by most of the Catholic world from the date of the papal bull of Pope Gregory XIII which was decreed on February 24, 1582, the British didnt werent part of the Roman Catholic realm. Through the Calendar Act of 1750, the British finally adopted the Gregorian calendar, but it became confusing for all of the English subjects in the realm born after that year.
In 1752, good old George Washingtons birthday under the British Empires newly adopted Gregorian Calendar, became February 22, 1732. Not to be outdone, the U.S. Congress decided to add to the calendar confusion, and on January 1, 1971, the Uniform Monday Holiday Act took effect and transformed several traditional holidays celebrated throughout the year to Monday dates, This included the remembrance of Washingtons Birthday. So, contrary to popular perception, this legislation did not establish a Presidents Day to combine Washingtons and Lincolns birthday parties.
Read more: http://communities.washingtontimes.com/neighborhood/history-purpose/2013/feb/17/presidents-day-or-george-washingtons-birthday/