Amtrak will move its Penn Station operations across Eighth Avenue to the historic Farley Post Office Building on Jan. 1, the railroad said.

The $1.6 billion facility — dubbed Moynihan Train Hall after the late Sen. Daniel Patrick Moynihan — adds 50 percent more waiting room to the notoriously dingy and crowded Penn Station, according to state officials. Travelers will be able to connect from the new train hall to Amtrak, the Long Island Rail Road and the Eighth Avenue subway.

Work on Moynihan Train Hall began in 2017. The 255,000 square-foot train hall features a 92-foot skylight, which will provide a stark contrast with Amtrak’s dimly-lit hall under Madison Square Garden.

The Post Office Building itself contains 740,000 square feet of office space, the Times-Union said. Facebook is the building’s primary tenant.

The number of tracks at the station remains the same, however. Gov. Andrew Cuomo in January put out a plan that would annex an entire block just south of the station to make room for eight new tracks.

Cuomo’s plan would require approval from the city.