Which is the last day that God created human beings?

Technically today, since God is the creator of all life! All mothers and fathers are participants (we use the term “co-creators”) in God’s act of creation when a child is brought into the world.

However, if you’re referring to the creation accounts, then Genesis 1:24-31 tells us that God created human beings on the 6th day, as the crown jewel of creation. Genesis 2, which tells the creation story from a different perspective, doesn’t say what day man and woman were created.