Since the dawn of time, man needed tools to measure time and help him in secular and religious matters. Questions like: When do we plant? When do we go to war? When should the tax collector show up? The dates of religious festivals and popular events all require a well-calibrated system and knowledge.
Islam is a monotheistic Abrahamic religion originated in the Arabian Peninsula 1400 years ago, and spread rapidly to form a majority of the population in the Middle East and many Asian and African countries. Islam now is followed by more than a billion people, making it the second largest religion in the world.
Sikhism is a monotheistic religion originated in northern India with around 27 million followers around the world, most of whom live in the Punjab region of India and Pakistan. It was founded by the Guru Nanak, also known as the First Guru in the 16th century.
Buddhism is one of the largest eastern religions in the world. It is embraced by more than 520 million people around the world, most of them live in East Asia, making Buddhism the fourth largest religion in the world after Christianity, Islam, and Hinduism.
Hinduism is one of the world's largest religions, followed by one billion people making it the third largest religion in the world. Most of the Hindus are in the Indian subcontinent. Nevertheless, they are not a religious majority except in India and Nepal. India has a Hindu population of 890 million.
Judaism is the oldest of the Abrahamic religions, and one of the oldest monotheistic religions in the world, it is 3000 years old. Judaism is associated with the Jewish people, since the religion is not a missionary faith, meaning that it is not open to people of non-Jewish origins. Today, the Jewish population is approximately 14.5-17.4 million.