My OR said that we "need" to have it in by the end of March. He sounded like it was pretty urgent so I would get your packet in ASAP. Even after you submit, your packet still has to go through several checks at NRC which can take 1 day to 1 month. All of my papers went to NRC on March 26, which is only 50 days since the last board, and I'm still afraid I might miss the next board. With all of the people who barely missed last board, I wouldn't be surprised if they are nearing or have already met the quota for packets for this next board.