Background: Ziaur Rahman, popularly known as Zia, was the second son of Mansur Rahman and Jahanara Khatun. His father was a chemist who specialised in paper and ink chemistry and worked for a government department at Writer's Building in Kolkata. As a child Ziaur Rahman, nicknamed Komol, was reserved, shy, quietly spoken, and intense in many respects. He was raised in Bagbari village, Bogra and studied in Bogra Zilla School.
Context: Graduating from the Pakistan Military Academy at 12th PMA long course on 18 September 1955 in the top 10% of his class, Ziaur Rahman was commissioned as a second lieutenant in the Pakistan Army. In the army, he received commando training, became a paratrooper and received training in a special intelligence course.  Zia went to East Pakistan on a short visit and was struck by the negative attitude of the Bengali middle class towards the military, which consumed a large chunk of the country's resources. The low representation of the Bengalis in the military was largely due to discrimination, but Ziaur Rahman felt that the Bengali attitude towards the military perhaps prevented promising young Bengali from seeking military careers. As a Bengali army officer he advocated military careers for Bengali youth. After serving for two years in Karachi, he was transferred to the East Bengal Regiment in 1957. He attended military training schools in West Germany and UK. He also worked in the military intelligence department from 1959 to 1964.  Ayub Khan's highly successful military rule from 1958 to 1968 convinced Zia of the need for a fundamental change in the Bengali attitude towards the military. During the Indo-Pakistani War of 1965, Ziaur Rahman saw combat in the Khemkaran sector in Punjab as the commander of a company unit of 300-500 soldiers. Ziaur Rahman won the prestigious Hilal-i-Jur'at medal, Pakistan's second highest military award, and his unit won 2 Sitara-e-Jurat (Star of Courage) medals, and 9 Tamgha-e-Jurat (Medal of Courage) medals, for their role in the 1965 War with India. In 1966, Zia was appointed military instructor at the Pakistan Military Academy, later going on to attend the Command and Staff College in Quetta, Pakistan, he completed a course in command and tactical warfare. Zia helped raise two Bengali battalions called the 8th and 9th Bengals during his stint as instructor. Around the same time, his wife Khaleda Zia, now 23, gave birth to their first child Tarique Rahman on 20 November 1964. Zia joined the 2nd East Bengal regiment as its second-in-command at Joydebpur in Gazipur district, near Dhaka, in 1969, and travelled to West Germany to receive advanced military and command training with the German Army and later spent a few months with the British Army.
Question: How long was he in the military for?

Answer: