While lobster can live out of water for a day of more when stored in the refrigerator between 36 and 45 degree, for best result we suggest that you cook them the day they arrive.
The best way to keep lobsters alive for up to 24 hours is to store them in a lose paper bag with damp newspaper or in the shipping container in the coldest part of the refrigerator (usually the lowest shelf at the back or in the meat keeper). Don’t even think about the freezer!
If for some reason you find that you cannot prepare the lobsters for more than a day, you may partially cook them. After you have par-cooked them, submerge in cold water for 3 minutes, drain, and refrigerate. You can finish cooking them any time up to 48 hours later. Cooked lobster meat may be refrigerated in an airtight container for 2-3 days, or for months if frozen.