Ancient people did not have the same feelings about history and dating that we do today. Of the six world religions Hinduism is the oldest, although we cannot put a precise date on it as it emerged from a range of religious beliefs brought into the Indus valley by the Vedic Aryan tribes about five thousand years ago.
The adjective Hindu appeared during the Mughal rule of India around 1200 C.E. and the term Hinduism is even later, dating from British colonial rule in the 19th century.
The next oldest religion, Judaism, began with the covenant made by Abraham nearly 2,000 years B.C.E.
The most recent of the world religions is Sikhism which began in the 17th century.