In most Muslim countries, the week begins on Saturday and ends on Friday. This goes for work/school as well as worship. Whats more, the Jewish Sabbath begins at sunset on Friday... Also Roman Catholics hold a special importance on Firdays, having to refrain from eating "land animal's meat" on fridays... While Eastern Orthodox Christians also observe Friday as a time for fasting.
A better question is why did some Christan sects decide Sunday should be the Sabbath?
A better question is why did some Christan sects decide Sunday should be the Sabbath?
