Complex sentence: Day was commissioned as a Lieutenant in the US Army Infantry and stationed at Fort Benning, Georgia for training in 2007, where he completed the Infantry Officer Basic Course, Airborne School, and Ranger School.
Split into simpler sentences: Day was commissioned as a Lieutenant in the US Army Infantry and stationed at Fort Benning, Georgia for training in 2007. While at Fort Benning, he completed the Infantry Officer Basic Course, Airborne School, and Ranger School.