607 -2520 plus 1 equals 1914
Why are you adding 1? The zero year is subtracted, not added.
Here, consider this:
o o o | o o
Here I have six total points in space, represented as o and the origin as |
So the point on the far left is -3, and the far right is +2. What is the distance between -3 and +2? It's 5 from one to the other, and 4 in between, including the origin. (This is told by -3 + 5 = 2. Note that I am not adding 1 and the origin is included.)
However, in our case, there is no zero year, so there is no origin... So you subtract 1.
Why are we adding 1 instead?