Daniel asked: Why did God create in six days?
It's true that God could have created the universe in six days, six hours, six minutes, six seconds, or even instantly. God is infinite and is not bound by time or space. His power, knowledge, and wisdom are all infinite.
He could have created anyway that He wanted.
But we know why He chose to create in six days from what He said to Moses in Exodus 20:9-11.
In Exodus 20:9, God established the pattern of a seven-day week. Again, He could have created any pattern that He wanted to, but He chose seven days.
We are to work for six days of the week. We are to set aside one day for rest and worship.
The reason God gave for setting up this pattern is because it’s the pattern God followed. Verse 11 says “For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy” (ESV).
That is clearly a reference to the creation week. So, of all the ways God could have created, He chose to create in six days and rest for one so that we would have a pattern to follow as we organize our lives around the seven-day week.