Unthinkable (if you are Greek, Italian or Spanish). ;)
You may have to go to a specialty market for special types, but most supermarkets do sell the (canned) black olives both with and without their pits.
I am sure they are still edible if they are not showing signs of decay and or mold. Most olives are pickled in brine which preserves them for a long time without the need for refrigeration. If they have been kept sealed in a jar they will keep much longer than 4 days--probably weeks and possibly months. If the olives are not pickled (as some ripe olives are not), and they are left exposed to the open air, they might begin to spoil within 4 days. Otherwise there is not likely to be a problem.
olives
A type of olives
Green olives are a little unripe, but still ready to eat. Black olives are the same olives, but much riper. Green olives turn black as they mature.
Olives
olives hav no cholestrol
· kalamata olives
olives vertes
Olives put hair on your chest. (joke).
olives are found in fields and on trees
Jesus prayed on the Mount of Olives before He was crucified. "On olive's brow" means on the Mount of Olives.