In 1963, the Fair Sabbath Law went into effect, permitting Shabbat-observant Jews in New York City to do business on Sunday. Throughout much of the 20th century, one of the biggest barriers to Shabbat observance in America was a work week that included Saturday, yet precluded Sunday. New York, with the largest concentration of Jews outside of Israel, has innovated numerous laws designed to accommodate religious expression for all faiths.