DRW 5 Day Survivor

 is a Dead Rising achievement. Survive for 5 days (10 hours real time) in Infinity Mode. The reward is the Laser Sword arguably the most powerful weapon in the game.

Trivia
If Frank is in the security room when the 5 day survivor achievement is accomplished, the laser sword will not appear. Frank must leave the security room to another load screen, then return again for it to appear.