For Christians Sunday is an important day. We are obliged to go to Church and worship God. Christians should rest from unnecessary labour on Sunday. For Jews Saturday is an important day. On Saturdays Jews go to the synagogue to worship G-d. Jews do not work or conduct business on the Sabbath. It is my understanding that the most important day of the week for Muslims is Friday. I also understand that the main act of worship on Fridays is midday prayers. However, it seems that Muslims go about their normal business on Friday. Why does Islam not require Fridays to be a day when all unnecessary work is set aside?
Christians celebrate Sunday because it is the day Christ rose from the dead. Jews celebrate the Sabbath on Saturdays because it is the seventh day of the week, the day on which G-d rested after creating the universe. Why does Islam have Friday as its principal day for religious observance?