February 22 became a national holiday in 1880, celebrating the birth of George Washington, and it was celebrated on that date until the Uniform Monday Holiday Act moved it to the third Mondays of February. Popular tradition has combined it with the February 12 birthday celebration of Abraham Lincoln’s birthday, which although observed as a holiday in many states, was not a federal holiday. There is occasional grousing about moving the holiday from the actual birthday of our first President, but Washington wasn’t actually born on February 22, 1732, but February 11, 1731.
When the Catholic countries of Europe began to change from the Julian to the Gregorian Calendar, named for Pope Gregory XIII, in 1582, the Protestant countries, including England, declined to follow this new calendar, which began when Thursday October 4, 1582 was followed by Friday October 15, 1582, dropping 10 days from the calendar. Over the next 170 years, various countries adopted the changes, until finally, England, and her colonies joined in by following Wednesday February 17, 1753 with Thursday March 1, because by this time it was necessary to drop an additional day.
Also in England, the civil new year had started on March 25, making January through March 24 in England and her colonies a different year than that recognized by most of Europe. The new year switch occurred in English holdings when 1751 ended on December 31, with 282 days.
George Washington was born before these changes took place, on February 11, 1731/32. This “double dating” was common in English records of the time, where clerks and other record keepers were cognizant of the need to make the documents clear as to date. After the change, George, like many who believed that the days of his life were truly numbered, did not want to lose any bit of the life allotted to him to celestial clerical errors, adopted February 22, 1732 as his birth date.