This Monday is the federal holiday Washington's Birthday, better known as Presidents Day, celebrated on the third Monday of February. If you want to know the actual birth date of George Washington, you will find two dates: Feb. 22, 1732, and Feb. 11, 1731. Both dates are correct. What accounts for the discrepancy? When Washington was born, Britain and its colonies were using the Julian calendar. Developed in first century B.C. under Julius Caesar, it had three too many leap days per 400-year period. The Catholic Church corrected the error in the 16th century by introducing a modified calendar (the...