Thanks for that!
The Talmud tells us that the soul of Adam was created at five and a half days after the beginning of the six days. That is a half day before the termination of the sixth day. At that moment the cosmic calendar ceases and an earth based calendar starts. . How would we see those days stretched by a million million? Five and a half days times a million million, gives us five and a half million million days. Dividing that by 365 days in a year, that comes out to be 15 billion years. NASA gives a value of about 14 billion years. Considering the many approximations, and that the Bible works with only six periods of time, the agreement to within a few percent is extraordinary. The universe is billons of years old from one perspective and a mere six days old from another. And both are correct!
The five and a half days of Genesis are not of equal duration. Each time the universe doubles in size, the perception of time halves as we project that time back toward the beginning of the universe.