The tree light show takes place nightly, every half hour from sundown to 9 p.m. Now through January 3, ignite your holiday spirit with the lighting of the 56-foot tree and two million twinkling lights in the Waterfront District at National Harbor. Ignite your Holiday Spirit with a Festive Tree Lighting Every Night Here are nine ways to celebrate the season at National Harbor:ġ. National Harbor’s popular holiday celebrations takes place throughout the destination with events and activities all season long for the whole family. NATIONAL HARBOR, Md., December 17, 2020-Celebrate the holidays at the Washington, D.C.