UPDATE: I'm FAKE NEWS, SEE DESCRIPTION: FFXI - WAIT! Don't Do Your Monthly A.M.A.N. Trove Quest..YET

********UPDATE: It seems I was mistaken, you CAN in fact do it right away. Thanks to the person who pointed that out! I'm FAKE NEWS!!!

Wait for it... literally. Until May 16th
ALTHOUGH!
Feel free to start gathering your Silver Vouchers in the meantime, just don't use them until JP midnight on the 16th!