I didn’t have the faintest idea

Food safety experts agree: if the salad was cooked with fresh ingredients, kept cold, and never left out, it’s safe up to five days—but only if controlled correctly.
Don’t depend on luck or personal anecdotes. Label the date, avoid double-dipping, and chill leftovers immediately. When in doubt, toss it out. It’s safer to delete a meal than risk getting sick.