How long is one kalpa or 一劫?

#1

In 35 Buddhas Repentance, by reciting the name of the various Buddhas, you are able to repent for your sins in 1 kalpa or 一劫?
How long is that in human years?

#2

From Wiki, it seems that there are different kinds of kalpa:

In another simple explanation, there are four different lengths of kalpas. A regular kalpa is approximately 16 million years long (16,798,000 years[4]), and a small kalpa is 1000 regular kalpas, or about 16 billion years. Further, a medium kalpa is roughly 320 billion years, the equivalent of 20 small kalpas. A great kalpa is 4 medium kalpas, or around 1.28 trillion years.

I wonder which kalpa is referred to in the 35 Buddhas Repentance?
Anyone can help?