That would depend on which god you refer to.
6 days
They are pretty much identical except that in the Islamic version the Creation ends after six days. God does not rest on the seventh day, because God would not need to rest.
God created days. He invented days in the seven days of Creation.
rest
The six days of creation story in Genesis serves to illustrate the power and creativity of God in bringing forth the world and all living things. It establishes the order and purpose of creation and emphasizes the importance of rest on the seventh day, known as the Sabbath. It also sets the foundation for understanding humanity's role as stewards of God's creation.
As it says in the bible, The seventh day was to be the sabbath, the holy day. Not every day is holy, just the sabbath, the day of rest, for that's when God finished his creation of the Earth.
In the Christian perception of God, he should never need to rest, thus making the seventh day an anachronism. However, the Jews wanted to know why they were required to hold the seventh day to be a day of rest. One version of the Ten Commandments says that God commanded the Israelites to respect the sabbath day because that was the day on which God rested.
God rested on the seventh day to set an example for humans to take time to rest and reflect on their work and to acknowledge the completion of creation.
On the sixth day of creation, God created land animals and finally created human beings in his own image. On the seventh day, God rested from his work of creation, blessing and sanctifying the day as a day of rest, known as the Sabbath.
rest
Depictions of the Creation week can be found at the Related Links below.
Serve God with free will. Even angels cannot do that. See also:Is there evidence for Creation?Can you show that God exists?