John Kennedy actually said...
By virtue of the authority vested in me as President of the United States, it is hereby ordered that employees of the several executive departments, independent establishments, and other governmental agencies, including the General Accounting Office, the Government Printing Office, and the field services of the respective departments, establishments, and agencies of the Government, except those who may for special public reasons be excluded from the provisions of this order by the heads of their respective departments, establishments, or agencies, or those whose absence from duty would be inconsistent with the provisions of existing law, shall be excused from duty on Monday, December 24, 1962, the day preceding Christmas Day.
11/20/1962