Why does the whole world observe a 7 day week?

Our month is based on the moon, our year on the sun, but what
about a week? The seven day week is based on God’s creation
week. Atheist dictator Stalin tried to erase God from the Soviet
Union by instituting a 10 day week. People would work nine days
and then rest the tenth day. It was not successful because people’s
bodies could not stand the strain of working nine days with only
the tenth day of rest. Others have also tried to eradicate the seven
day week, but to no avail. The pattern of a seven day week is a
reminder of God creating everything in six days and resting on the
seventh day.
We also find God reminding us of this pattern in Exodus 20:8-10,
“Remember the Sabbath day by keeping it holy. Six days you shall
labor and do all your work, but the seventh day is a Sabbath to the
Lord your God, on it you shall not do any work… For in six days
the LORD made the heavens and the Earth, the sea and all that is
in them, but he rested on the seventh day.” Here we see the pattern
for a week repeated again; work six days and rest the seventh day.
The God of all creation could have created everything in a split
second, but He did not. This all powerful God knew what we
needed; He knew what our bodies could handle. From the very
beginning of time, He set the pattern for a seven day week – for our
Then he said unto them “The sabbath was made for man, not man for the
sabbath.” – Mark 2:27