Thanks for posting that, Prince. I'm reproducing my post from the Vermont forum.
The cutoff dates will not move linearly i.e., it won't be 1 month for every month or at a constant speed. These are estimates of some no-name clerk or bureaucrat in Washington DC. They are humans and will err.
For India,
EB2 has moved from Nov 99 to Jul 2000 in 2 months.
EB3 has moved from Jan 98 to Jan 99 in 2 months.
Both of these are because the bureaucrats in DC overestimated the waiting line (and screwed all of us). Now they realize there are not that many people with PDs in 98 or 99. So they moved it forward quick.
I predict that the dates will move forward rapidly for both EB2 and EB3 until they reach April 2001. Once the cutoff dates reach April 2001, it will stay there for a very, very long time. If your priority date is before April 2001, hang in there, it's not long. If you're after, it's bad news for you.