If your freezer was just left open and the cold was still pumping through it than I would say anything that is still frozen can still be held on to. If it has unthawed (like frozen steaks) and you should eat it that day or the next.
if your freezer was left open and temperature inside the freezer is still maintained less than 30 degree centigrade it will last for long time. suppose the ice crystals inside is maintained the temperature below 30 its ok. otherwise the food will affected by bacteria and cant use for eat.
The food will 'last' a very long time, perhaps several years. However, after just a few days or weeks the food can get freezer burn. Although the food may still be good, it will be infested with icy crystals.