Yes, that is the official date, but if the miners start dropping off then the network slows down to a crawl.
I honestly don't know why people waited till the last minuted.
The GRCX blockchain won't sync no matter the nodes I add. So that makes the conversion impossible I suppose.
Which begs the question, how to do it now?
It's late but it was cited: "CONVERSION DEADLINE: 20TH APRIL 2015"
I tried a week or two ago for the first time. I thought it would be more than enough time, especially because of the given date on Gridcoin.us