(Creation Week to Catastrophe 1)
Calendar Years 2256 years long (Ediacaran not included)
Atomic years (from Hadean on) 3.9 billion years long (Ediacaran not included as standard geology is currently revising the dates and classifications of this time to include the Ediacaran, although it is after the "Snowball Earth"/Flood catastrophe)
At the initial point of Creation, light speed 6.25 x 1011 times current speed
At the end of Creation Week, it was down to 340 million times its current speed.
This era closes with Catastrophe 1. In standard geology it is often referred to as the time of "Snowball Earth." In the Bible is it Noah's Flood. It is also the time of the initial axis tilt of the earth.
At the close of this era, light speed was about 1.38 million times is current speed.
(Cambrian to Permian)
Calendar years -- 372 years long
Atomic Years -- 479 million years long
This era closes with Catastrophe 2: In standard geology it is the time of the Permian Extinction. Biblically, this corresponds to the destruction of the Tower of Babel.
At the close of this era, the speed of light was 1.2 million times its current speed.
(Triassic to Cretaceous)
Calendar Years -- 159 years long
Atomic Years -- 185.5 million years long
This era closes with Catastrophe 3. In standard geology it is the K/T Extinction. Biblically this corresponds to the time of Peleg and the beginning of the separation of the continental plates. This time is also marked by a much higher axis tilt.
Light speed at the close of this era was about 1.13 million times its current speed.
(Paleogene to Quaternary, to the end of the Ice Age)
Calendar Years -- about 678 years long
Atomic years -- about 65.5 million years long
The light speed curve is now flat enough to show the oscillations.