Sunday for most Christian-based faiths was established through history rather than scripture. There is nothing in the New Testament to designate sunday as the sabbath. When Emperor Constantine I came to power he legalized Christianity and made the first Sunday keeping law in the year 321. Constantine's Sunday enforcement law was officially confirmed by the Council of Laodicea in the year 364. The later adoption of the Gregorian calandar later helped to cement sunday as the sabbath.