The 2520 By Royal Decree 

Note - Video Update Correction
This video was produced shortly after we had first begun to study the 7 Times prophecy and we were still in the learning process. Since the production of this video, we have learned so much more about the 7 Times (2520) - It is truly a fascinating prophecy with tons of parallels and connections. However, I do need to make a couple corrections to a couple things I stated in the video.
The first correction is that I mention that the Millerites didn't realize that there was no "0" year between BC and AD and this was where they made their mistake - This statement in the video was incorrect - which I didn't realize until later upon reading some of their statements on the matter. 
The Millerites were very intelligent and they all realized that time went from 1BC to 1AD. The "mistake" didn't involve the transition between BC and AD at all. The mistake was actually referred to in their writings as "the Full Year" concept. Where they made their mistake, was that they forgot to take into account that a time prophecy would be "full years" of time. In other words, when they calculated the 2300 days from 457BC to 1843 - they didn't account for the fact that the decree went forth in the autumn of 457BC instead of the first day of 457BC - which would make the end of the prophecy move that many months forward in time - therefore taking it to the autumn of 1844 instead of the last day of 1843.

The second correction is that when I am showing the comparison between the 7 Times prophecy and the One Week of Christ's ministry, I refer to the one week as 2520 literal days and the two 3.5 periods in the one week as 1260 literal days. This is also incorrect. Upon further study and calculation, what we discovered is that the One Week of Christ's Ministry is rather a Prophecy "Parallel" comparison, not a "specific time" comparison.
In the Prophetic Time (Day for a Year), a year is calculated as 360 days, whereas, our literal year is 365 days.  In other words, "Prophetic Time" is the measuring rod, and "literal time" is what is being measured. Our Pioneers correctly understood this concept - we are just a little slow in relearning it.
Example: 1 "Prophetic" Year (Time) = 360 "Prophetic" Days = 360 Literal Years
1 "Prophetic" Day (cannot be numbered as 360 Literal Days as our literal years are 365)
What this means is that the 7 Times (2520 year) prophecy which is divided into two 1260 year periods of the reign of Paganism and Papalism - is a "parallel comparison" with the "one week" (7 years) of Christ's ministry, which is divided into two 3.5 year periods. 
It is a parallel comparison only. 
If you switch from "Prophetic Time" to "Literal Time" - such as what I did in the video when I claimed that the 7 years was 2520 literal days and the 3.5 years of Christ ministry was 1260 "literal" days - then you run into miscalculations as the "literal year" is always a little over 5 days longer than a "prophetic day!" I made the mistake of mixing "literal" and "prophetic" time.
In short, you can see the comparison between the "7 Times" (2520 literal years) and the "1 Week" (7 literal years) - and you can see the comparison between the 2 (1260 literal years) and the 2 (3.5 literal years) - but you cannot compare the "prophetic time" of 360 days in a year to the "literal time" of 365 days in a year.
So when you reach this section in the video, just realize that the "literal days" in the "one week" of Christ and His Church, are not correct and ignore that "literal days" part of the parallel.

More info on the Seven Times of Leviticus 26!