In 7th grade, they taught us the sales discount equation. I learned then that 40% off is not the same as 40% more than the discounted price. You are usually in the same ballpark, but you might be short of the wall by a few meters (or maybe many) meters.

My mistake is falling for the continuity trap. If we put the non-swapped values into the continuous formula, we get the same answer as before:

265 = 937*e^(-0.015*t)
ln(265) = ln(937) -0.015*t
t = (ln(265 – ln(937))/(-0.015) = 84.1969 years

However, putting the correct values into the correct formula give us a slightly different answer. If we set A = 265, P = 937, r = -1.5%, and n = 1; we get:

265 = 937*(1 -0.015/1)^(1*t)
ln(265) = ln(937) +t*ln(0.985)
t = (ln(265) – ln(937))/ln(0.985) = 83.5638 years.

But we can’t get 265 exactly. We are slightly above it at 83 years and slightly below it at 84 years.

If you don't know math, you can also calculate it using excel:
type 937 in box A1
type =A1-0.015*A1 in box A2
drag down
in box A85 you'll see the number 263.2588
So after 84 years.