There's a drop down allowing you to see rankings posted longer than 14 days ago. Outside of coaching changes, I think there would be little changes to the dynasty rankings of players from 30+ days ago.
Not sure if I can explain this, but I'll give it a shot. I think we are all aware of the drop-down box to display rankings from farther back. But the point is that you
can't get to that interface right now. You can only get there
if someone has some rankings posted within the past fourteen days. It's a Catch-22.