The Constitution of India initially permitted the use of English language for all official purposes for period of:

Explanation

As provided in Article 343(1) of the Indian Constitution, Hindi in Devanagari script is the official language of the Union. But, as per Article 343(2), it was laid down that English would continue to be in use as the official language for the work of the Union for a period of 15 years from the date of the applicability of the Constitution that is up to 25th January 1965.