That is true of Young Earth creationists but NOT true of
Old Earth creationists.
Progressive creationism, Theistic evolution, and Hindu creationism do NOT hold to the creation in the six days of Genesis idea.
In Hindu creationism the universe exists for one day of Brahma (
4.32 billion years) and is destroyed as the end of the day. Brahma then rests for a night equal to the length of the day (
4.32 billion years) and at the end of the night makes a new universe.
As Carl Sagan commented in his show Cosmos day and night of Brahma is "longer than the age of the Earth or the Sun and about half the time since the Big Bang"
Day-age creationism does hold to creation in the six days of Genesis idea
but it uses Psalm 90:4 and 2 Peter 3:8 to argue a day of God is not one of our 24-hour days but longer--in the range of thousands if not millions of years.
Cosmic Time is Day-age creationism on steroids with one "day" being
2.5 billion Earth years and the whole "six days" lasting
15 billion Earth years.
So when talking about creationists remember not all of them are part of the young Earth group.