The Uniform Monday Holiday Act (Pub. L. 90–363, 82 Stat. 250, enacted June 28, 1968) is an Act of Congress that amended the federal holiday provisions of the United States Code to establish the observance of certain holidays on Mondays. The Act was signed into law on June 28, 1968, and took effect on January 1, 1971, and did not officially establish “Presidents Day”, nor did it combine the observance of Lincoln’s Birthday with Washington’s Birthday. But the act placed federal observance of Washington’s “birthday” in the week of February 15 to 21 and, since that week always falls between Lincoln’s birthday (February 12) and Washington’s (February 22), but never includes either date, popular references have given rise to the title, which recognizes both Presidents.

In New York, General Construction Law Section 24 designates both Lincoln’s Birthday and Washington’s Birthday as a separate state holiday:

“§ 24. Public holidays; half-holidays. The term public holiday includes the following days in each year: the first day of January, known as New Year’s day; the third Monday of January, known as Dr. Martin Luther King, Jr. day; the twelfth day of February, known as Lincoln’s birthday; the third Monday in February, known as Washington’s birthday; the last Monday in May, known as Memorial day; the second Sunday in June, known as Flag day; the fourth day of July, known as Independence day; the first Monday in September, known as Labor day; the second Monday in October, known as Columbus day; the eleventh day of November, known as Veterans’ day; the fourth Thursday in November, known as Thanksgiving day; and the twenty-fifth day of December, known as Christmas day, and if any of such days except Flag day is Sunday, the next day thereafter; each general election day, and each day appointed by the president of the United States or by the governor of this state as a day of general thanksgiving, general fasting and prayer, or other general religious observances. The term half-holiday includes the period from noon to midnight of each Saturday which is not a public holiday.”