Kirk told the Chicago Sun-Times his staff noted the mistake and fixed it in his official biography last week. Kirk said the change came before he heard from the Washington Post, which first reported the error Saturday.
Kirk traced his mistake to a faulty recollection when he was preoccupied with his first congressional campaign in 2000. "I am entirely responsible for this," he said. "I have a great staff. They are the ones who found it."
The congressman said his opponent's criticism of the mistake amounts to an attack on his 21 years in the Naval Reserve. Kirk faces Democrat Alexi Giannoulias, who has no military record, in the general election in November.
"When I was wearing a uniform in Aviano, I think he was wearing the uniform of a basketball team in Greece," Kirk said, referring to an assignment in Italy for a NATO campaign in the late 1990s. Giannoulias played professional basketball overseas before returning to Illinois and later getting elected state treasurer.
Giannoulias said he intended no disrespect for Kirk's military service but was questioning Kirk's misstatements. "What a lot of folks are sort-of sick and tired of is a typical Washington D.C. sort-of insider politician where they embellish their records," he told WBBM-AM radio.
Kirk also has had to backtrack from comments that surfaced from a video in which he said, "I command the war room of the Pentagon." For his Naval Reserve duty, he works weekends as a deputy intelligence director at the National Military Command Center, the war room's formal name. The commander usually is a one-star general.
"This is where legal precision becomes important in a Senate campaign," Kirk said. He said he prefers "to speak in plain English" but will be more careful in campaign appearances.
Both politicians were involved in a Memorial Day remembrance in Arlington Heights that was cut short by thunderstorms. Giannoulias then traveled to President Obama's appearance at the Abraham Lincoln National Cemetery in Elwood, which also was rained out.