how do i reset my start date?

i'm traveling this next week, and i'd really like to hit this hard (i've order all the preliminary stuff) when i get back. i'd like to study it for a day or two to plan my groceries (i saw the list, but i'm worried i'll mess up quantities, so i want to scope as many days ahead of time and plan this so there's no surprises and i can hit it hard).

is there a way to reset my challenge start date (30 days six pack sprint)?