[jr2]

http://www.fanfiction.net/s/5782108/71/Harry_Potter_and_the_Methods_of_Rationality

That's chapter 71.  The chapter number is right before the end of the url, see?  /71/Harry_Potter_and_the_Methods_of_Rationality  Change the number and the chapter number changes.  Or just, you know, hit the "Next" button. 

[Marcov]

So how much does this thing cover, actually? The whole series?

[jr2]

Hmm, I don't know.

[Bob-san]

So how much does this thing cover, actually? The whole series?

Up until the author decides to stop writing I suppose.

[Marcov]

The book's up to 71 chapters. Since when have you (jr2) been reading this, anyway? Last month?

[jr2]

Somewhere between the 10th and 12th of April of this year?

[Marcov]

You read 71 chapters in 2 days? Wtf?

[sigtau]

Time difference between the time jr2 posted on the 17th and the 10th or 12th is anywhere between 7 and 9 days.  Your math is botched.

[Dilmah G]

You read 71 chapters in 2 days? Wtf?

That's when he started reading dude, not when he started and finished.

[jr2]

Correct; I've been reading since the 10th or 12th.

EDIT: I checked my history on my desktop (where I started reading); it was the 11th, in case any are curious. 

EDIT2: And I just realized, sigtau... your math is less botched, but still botched:

Time difference between the time jr2 posted on the 17th and the 10th or 12th is anywhere between 7 and 9 days.  Your math is botched.

17-12=5; 17-10=7, so, between 5 and 7 days.    In this case, 6.