Busy people, especially during stressful times, often lose track of what they have in the fridge and when they put it there. I always say, when in doubt, throw it out.  Better yet, keep a black felt-tip marker right by the refrigerator, and before you store opened cans of tomato sauce or paste, black olives, broth, bottles of spaghetti, pizza or apple sauce, or other such items, write the day on it with the marker.  If not used within a day or two, freeze the contents in either ice cube trays, small freezer keepers such as Tupperware has, or in freezer bags (label please!).  You'll cook with more confidence, save money and avoid some of those cases of "stomach flu".