How long is the span of time from beginning to scratch the Scratch Construct to the Scratch actually occurring?

Thankfully for you we have a canonical answer to this! Since [S] Cascade actually has a countdown, we can assume that every second of Flash Animation is effectively one real second in the Homestuck World.

It takes John 8 minutes and 56 seconds to fully Scratch the Beat Mesa, so let’s say 9 minutes to Scratch the Construct. The next time we see the Scratch Construct is in the quick succession of images before the Countdown runs out, which is almost exactly one minute later. 9 minutes to make the Scratch, 10 minute for the Beat Mesa to ascend high enough that Skaia begins to receive the vast amounts of energy it creates, and finally, about 13 minutes and 14 seconds from the Beginning of the Scratch until it finally-

…

Of FUCKING Course it would be a 413 variant.