Day T is not set.
It depents on patience and greed
So Day T will be distributed over some time, possible years.
It can help to aviod appearence of Day T on day 1. Even on day 100, 200 etc.
Take a look at Coingather - there are hundred of millions ready to dump. But there are no buy side - no possibilities to dump now.

Once conversion to new coin will be in place - all these hundred of millions will be dumped ruining the exchange rate of new coin to virtually zero.