Bitcoin Core – How is “progress per hour” calculated?

Stickies-v provided the positions where it is calculated in the code.

Basically, it does what you’d expect for finding the percentage change in a quantity.

1. Milliseconds elapsed between first block and sample block:
   Δt = t_FirstBlock – t_SampleBlock

2. Sample blocks are processed a few milliseconds faster than the first block.
   ΔProgress = t_FirstBlockProcess – t_SampleBlockProces

3. We provide:
   (% progress per hour) = ΔProgress / (Δt × 1000 × 3600),

Where (1000 × 3600) = milliseconds in 1 hour.

^{In reality, both Δt and Δprogress are negative, but the ratio in step 3 above is positive.}