It is Jack-o-Lantern time! I always wait until the last minute to carve my pumpkin because it seems like it starts to rot the next day. I saw a special on TV where they immerse the cut pumpkin in a solution of water and bleach. You keep it in for a while and make sure it gets submerged and every cut surface is treated. Let it drain for a while.
Source: TV special Extreme Hallowe'en I think it was
This page contains the following solutions.
Combine equal parts of white vinegar and water in a spray bottle, shake and spray all cut areas of your pumpkins and they will not get soft, rot, or shrink for a long time.
To prolong the life of your jack-o'-lantern after making the cuts, coat the cuts with petroleum jelly.
