This seven-day week is not something that can, or should, be tinkered with, although some have tried to. In 1793, France, in an effort to increase human productivity, de-Christianized the calendar by modifying the seven-day week to a ten-day week. New clocks were even invented to reflect the revised week.
The experiment, however, radically failed: suicide rates skyrocketed, people burned out, and production decreased. Why? It turns out humans were not made to work nine days and rest only one in a week. We were made to work six days and rest one. The seven-day rhythm is sacred. The seven-day week is not the result of human ingenuity; rather, it is a reflection of God’s brilliance.