First, do you even know what the word "undisclosed" means?
It means that no time is given. Genesis 1:1 says that God created everything. When? It doesn't say. The time when God created everything is "undisclosed". That is, we're not told. But it was BEFORE the first day. How long before? It doesn't say. So neither can you.
Then it says, in Genesis 1:2, that the Spirit of God hovered over the face of the waters. This is a process. How long did God do that? It doesn't say. The time God took to hover over the waters is unspecified. So you don't know how long and it was BEFORE the first day.
What you've done is try to skip over the first two verses because they don't support your young earth tradition.