Weekend MARC train service, beginning Dec. 7:

Saturday

Nine round trips between Penn Station and Union Station:

Penn Station Departures: 7:35 a.m. to 9:15 p.m.

Union Station Departures: 9:02 a.m. to 10:35 p.m.

Sunday

Six round trips between Penn Station and Union Station:

Penn Station Departures: 9:15 a.m. to 5:30 p.m.

Union Station Departures: 10:40 a.m. to 7:00 p.m.

Weekdays

Two additional daily roundtrips between Penn and Union stations will be added, one likely this fall and another in the spring of 2014.