Congress passed the Uniform Monday Holiday Act in 1968, overhauling the federal holiday system and creating a standard federal holiday schedule. During vigorous floor debate, a proposal to name the third Monday in February Presidents' Day in honor of both Presidents Lincoln and Washington, whose birthdays both fall in the month, was defeated. At the time there was no federal holiday specifically honoring President Abraham Lincoln – only selected state holidays. So it remains today.
While the Uniform Monday Holiday Act moved the official observance of Washington's Birthday from February 22 to the third Monday of the month, its name remains Washington's Birthday.