Here's a holiday that defies intuition. First, the holiday was officially established as Washington's Birthday and remains so in the Federal Register. Second, Washington's Birthday will never take place on Washington's birthday. Okay, we'll tackle that last fact first.
George Washington was officially born in Virginia on February 11, 1731, but at that time, Great Britain and its little possession across the Atlantic (that's us) remained at odds with the Pope and still used the Julian calendar. To keep matters short, when the Gregorian Calendar was finally established in the Empire, Washington's birthday was recognized as February 22, 1732 -- give or take a Leap Year and other adjustments! However, it wasn't that easy!
The conversion from the Julian calendar to the Gregorian calendar is a matter of 11 days. However, when George was born, England's calendar was based on a Civil calendar-year ending in February, so when they adopted the Gregorian calendar, and the commonly accepted 'calendar year,' Julian dates from January and February were changed by a year and 11 days.
For poor George, since 1971, with the implementation of the 1968 Uniform Monday Holiday Act, his birthday is always celebrated on the third Monday of February, the earliest of which can be the 15th and the latest the 21st, meaning the holiday celebration never lands on his Julian or Gregorian birthdate.
Now, what about all that advertising for "President's Day Sale"?
The federal holiday to honor Washington began in 1879 for the government offices in Washington, D.C., and in 1885, it was recognized as a national holiday. In 1951, a movement to add a President's Day to the Federal calendar gained some Congressional support. However, it was never enacted into law. Later, Congress failed to enact new calls to combine the celebration of Lincoln's Birthday and Washington's Birthday into a single President's Day, keeping Washington's Birthday the official holiday.
Our President's Day celebration -- the one you see in all the store ads -- is just that: a mid-1980s advertising promotion that has become a part of our national identity.
You can learn more about Washington's Birthday at https://www.archives.gov/legislative/features/washington.