The bible speaks of 40 years in the wilderness and 400 years in Egypt, so now we have 4000 year cycles. Moreover, we was that a generation in the bible was 40 or 100 years. So now we have 40 times 100 years. We have either 40 or 100 generations---depending on how one looks at it. Thus the theme of generational cycles continues.

Moreover, 4000 years is commonly looked upon as symbolic of just 4 days in bible prophecy using the familiar biblical ratio of "a day is as a thousand years," (1Pet. 3:8, cf., Ps. 90:4). For instance, it is commonly believed that Jesus Christ came into the world about 4000 years from the creation according the biblical chronological record. Thus, Christ was born at the end of this great cycle---From the first Adam to the last Adam, (1Cor. 15:45). We are now half way through the second 4000 year cycle. But the most fantastic patterns emerge when we view the 4000 years as starting from the exodus consistent with how we have thus far already viewed it. But we must leave that for a later study. 

As said, the 4000-year cycles cause the average solar year to work out to 365.2425 days, which is the same as our modern (Gregorian) calendar. Now it 'happens' that scientists estimate that the solar year was just that---365.24250 days around 4000 BC! (The average length of a solar year is shrinking extremely slowly.) Hence, the traditional year of creation just 'happens' to have had a solar year of of exactly 365.2425 days---which generates these great 4000-year cycles, the first of which just 'happens' to have occurred at the birth of Christ!

The following is quoted off the Internet, "The Julian and the Gregorian Calendar" by Peter Meyer. The highlighting is mine.)

"...All agree, however, that due to the gravitational dynamics of the Sun-Earth-Moon system the length of the tropical year (however defined) is changing slowly. The length of the tropical year on 2000-01-01 is calculated by some astronomers to be 365.24218967 days, but at this level of precision the value depends on the definition of the concept. The value changes significantly with the millennia, however, as follows (according to a formula in common use among astronomers):

Year Length of tropical year in days -5000 365.24253 -4000 365.24250 -3000 365.24246 -2000 365.24242 -1000 365.24237 0 365.24231 1000 365.24225 2000 365.24219 3000 365.24213 4000 365.24207 5000 365.24201

Thus the value of the tropical year varies over this 10,000-year time-span by as much as .00052 days (about 45 seconds)." 

 

Therefore, at the creation, before sin and the curse, the tropical year was 365.24250, but by our time 6000 years later (at the end of the world?) it is now 365.24219. The difference between these two numbers is extremely slight, but as we shall see, God is using both numbers---that is, what the tropical year was originally created to be, and what it is now. They are in fact two witnesses to the One who created this clock. The prophetic clock uses both ends of this 6000-year spectrum.

The 365.2425 generates the said cycles of 4000 year periods. However, the current 365.2422 days (rounded from 365.24219) generates the need for 100,000-year cycles, or 1000 generations of 100 years. As we shall see, this is a most significant number! (We will look at the still more precise figure of 365.24218967 days in the second section of our study.) 

 

To step 5:
"Surpassing the accuracy of our Modern Calendar 
and Setting our Clock to 365.2422 days"