English was declared as the official language of Pakistan in:

English was declared as the official language of Pakistan in:

انگریزی کو پاکستان کی سرکاری زبان کب قرار دیا گیا
Explanation
Both Urdu and Bengali were declared as official and national languages of Pakistan in the 1956 constitution
English was declared as the official language of Pakistan in the 1962 constitution.