Depending on your context you may hear people talk about the six days of creation or the seven days of creation (or the day of creation if people are looking at the creation story of Genesis 2:4b-25). Really there is not much of a difference between saying that the earth was created in six days or that there were seven days of creation. The difference in these statements rests on whether one understands the Sabbath (or day of rest) as a key part of the creation story. For some people God resting is what God does after creation is finished, for others, the resting of God is an integral part of the whole act of creation. Really it is a question about the importance of Sabbath as a part of the week. Those who talk about the six days of creation, tend to see Sabbath as an extra addition. The only days that count in this understanding are days when actual work is being done. Those who talk about seven days of creation see Sabbath as an integral part of the week, just as important and meaningful a day as all those days where work is done.
The real point of the creation story in Genesis 1 is not to tell us how long it took God to create the world, but to emphasize the relationship between God and creation. In
the first creation story (Genesis 1:1-2:4a) God creates an ordered world in contrast to the chaos of the waters described in Genesis 1:2. There is an order to what God creates, and the story
emphasizes that what God has made is good. It also emphasizes that humanity is made in the image of God with purpose and that like all the rest of creation, the creation of humanity is
good. The message of Genesis 1 is not that God created the earth in six days nor that God created the earth in seven days. The message is that God created the whole world and all that is
in it, he created things so that all had their purpose, and he created it good.