It finished with the final examination called Reifeprüfung /Abitur (A-Level) at the end of the 12th grade, granting the Reifezeugnis, the certificate of eligibility for university entrance.
The EOS was established in 1959 to replace the hitherto existing Oberschule as laid down by the Act on Socialistic Development of the School System in the German Democratic Republic effective December 2, 1959.
The Ministry of Education determined a table of lessons (Stundentafel) which was mandatory for all extended secondary schools.
One lesson lasted 45 minutes and students went to school six days a week, from Monday to Saturday.
This table of lessons was effective until the reform of the existing Oberschule was finished and the newly established extended secondary schools were fully operational under the altered conditions.