On December 17, 2019, President Trump signs an Executive Order granting leave for most of the federal employees on Christmas Eve. Christmas Eve is not a regularly scheduled holiday, while the President has the authority to grant leave, it is usually announced just before the Christmas holiday.
It is normal for federal agencies to grant early dismissal for employees, but contractors are allowed to leave based on their contract or at the discretion of their government and (or) contract supervisor. The difference in departure times between federal employees and contractors always messes up afternoon slugs. Some drivers leaving early take regular lanes as they could not find riders that early and riders leaving late. Bus services including Omniride also try to start their services earlier, but it is hard to judge the early dismal timings which results in a long line of passengers at the Pentagon.
Last year, President Trump signed an executive order granting leave for all executive departments and agencies of the federal Government on Monday, December 24, 2018, the day before Christmas Day. In 2002, President George W. Bush gave federal employees a half-day.