is March 31....

If a the CC & GTCC BOD decide to invalidate the errored ballot immediately and end the VOTE, they can just as well,

Mail out a new ballot say on March 15(an arbitrayr date)Still over a month away should be plenty of time.

Make the Ballot return Date... May 15 (Almost 2 months of time for the voter to vote)

Still leaving them 14 days to count the ballots before the convention.

PLENTY OF TIME.