The subject of the 12th chapter of Daniel is the time of the end. His countdown includes 3 prophetic numbers that have intrigued expositors for centuries. They are 1260, 1290 and 1335. 1260 is never mentioned in Daniel. However, he does mention 'a time, times and a half' which the Book of Revelation equates to 1260.
There are a number of remarkable mathematical marvels that link these numbers together. The first three we will mention were taken from the
website of Kevin Heckle who has had a lifelong obsession with the time
periods in Daniel.
First, PI and PHI tie these three numbers EXACTLY. PI is the circumference of a circle divided by the diameter. PHI is the Golden Ratio, which permeates the design of God's universe.
PI = 3.14159264
PHI = 1.61803398
--------------
1.52355866 The difference of PI-PHI
(1260+1290) x (PI - PHI) = 3885 = (1260+1290+1335)
Second, all three numbers relate to the lunar and solar year.
--------------------------------------------------------
SQRT 1260 x 10 = 354.96 approx. lunar year
SQRT 1290 x 10 = 359.17 approx. lunar-solar average year
SQRT 1335 x 10 = 365.38 approx. solar year
Third, there is this seeming reflection.
------------------------------------------------------------------------------------------------------------------
1290 = 2.5 times 360 + 390. Whereas 1335 is the opposite:
1335 = 2.5 times 390 + 360.
Fourth, the seven times punishment is 1260 + 1260 = 2520 years.
-------------------------------------------------------------------------------------
During this time the solar year gains 75 years on the lunar year. 75 is the epact of 2520 years. Therefore, 1260 + 75 = 1335. Grattan Guiness goes into detail on this in Approaching End of the Age. The sun and the moon are time pieces set in motion before history to measure prophetic time periods.
The book of Daniel was written by the Creator of the universe.