The Church of the Holy City (Swedenborgian) will hold its Christmas Eve service at 4pm. Early, I know, but that can be useful for some Washingtonians.
The church is at the southwest corner of 16th and Corcoran (between Q and R) Streets, NW, in Washington.
Q Street east of 16th Street is a reasonable bet for parking, but transit is a better idea. S2 and S4 buses drop off at Q St., or take the Red Line to Dupont Circle. North exit, turn right off of the escalators, and walk on Q St. (note a theme here?) four blocks to 16th.
This is post #1100.