5 U.S.C. § 6103 : US Code - Section 6103: Holidays

      (a) The following are legal public holidays:
        New Year's Day, January 1.
        Birthday of Martin Luther King, Jr., the third Monday in
      January.
        Washington's Birthday, the third Monday in February.
        Memorial Day, the last Monday in May.
        Independence Day, July 4.
        Labor Day, the first Monday in September.
        Columbus Day, the second Monday in October.
        Veterans Day, November 11.
        Thanksgiving Day, the fourth Thursday in November.
        Christmas Day, December 25.

      (b) For the purpose of statutes relating to pay and leave of
    employees, with respect to a legal public holiday and any other day
    declared to be a holiday by Federal statute or Executive order, the
    following rules apply:
        (1) Instead of a holiday that occurs on a Saturday, the Friday
      immediately before is a legal public holiday for - 
          (A) employees whose basic workweek is Monday through Friday;
        and
          (B) the purpose of section 6309 (!1) of this title.


        (2) Instead of a holiday that occurs on a regular weekly non-
      workday of an employee whose basic workweek is other than Monday
      through Friday, except the regular weekly non-workday
      administratively scheduled for the employee instead of Sunday,
      the workday immediately before that regular weekly nonworkday is
      a legal public holiday for the employee.
        (3) Instead of a holiday that is designated under subsection
      (a) to occur on a Monday, for an employee at a duty post outside
      the United States whose basic workweek is other than Monday
      through Friday, and for whom Monday is a regularly scheduled
      workday, the legal public holiday is the first workday of the
      workweek in which the Monday designated for the observance of
      such holiday under subsection (a) occurs.

    This subsection, except subparagraph (B) of paragraph (1), does not
    apply to an employee whose basic workweek is Monday through
    Saturday.
      (c) January 20 of each fourth year after 1965, Inauguration Day,
    is a legal public holiday for the purpose of statutes relating to
    pay and leave of employees as defined by section 2105 of this title
    and individuals employed by the government of the District of
    Columbia employed in the District of Columbia, Montgomery and
    Prince Georges Counties in Maryland, Arlington and Fairfax Counties
    in Virginia, and the cities of Alexandria and Falls Church in
    Virginia. When January 20 of any fourth year after 1965 falls on
    Sunday, the next succeeding day selected for the public observance
    of the inauguration of the President is a legal public holiday for
    the purpose of this subsection.
      (d)(1) For purposes of this subsection - 
        (A) the term "compressed schedule" has the meaning given such
      term by section 6121(5); and
        (B) the term "adverse agency impact" has the meaning given such
      term by section 6131(b).

      (2) An agency may prescribe rules under which employees on a
    compressed schedule may, in the case of a holiday that occurs on a
    regularly scheduled non-workday for such employees, and
    notwithstanding any other provision of law or the terms of any
    collective bargaining agreement, be required to observe such
    holiday on a workday other than as provided by subsection (b), if
    the agency head determines that it is necessary to do so in order
    to prevent an adverse agency impact.