Yonathan Melaku, 23, was originally scheduled to be sentenced Friday. He is expected to get 25 years in prison for a series of overnight shootings at military buildings in Northern Virginia.
In addition to the Pentagon attack, he was linked to two shootings at the Marine Corps museum in Quantico and recruiting stations in Chantilly and Woodbridge.
The Alexandria man was arrested in June, 2011, after police caught him at Arlington National Cemetery with bomb-making materials in his backpack.
Melaku pleaded guilty in January to to injuring property of the United States, use of a firearm during a crime of violence and attempted injury to veterans' memorials on U.S. property.
Under the terms of his plea agreement, he would serve 25 years in prison.