Dates don't usually get thrown out because they spoiled overnight. They get thrown out because a bag sat open at the back of a cupboard for two months and hardened into something nobody wants to eat plain anymore. That's a storage problem, not a shelf-life problem, and it's fixable.
Keep an opened bag in an airtight container, not the paper or plastic sleeve it came in — that sleeve lets air in every time it's rolled and unrolled. A jar or a sealed box at room temperature keeps a drier variety like Mazafati or Deglet Noor in good eating condition for weeks. Once you notice the skin starting to wrinkle and toughen, that's the signal to move the rest to the fridge.
Hardened dates aren't waste yet
A date that's gone leathery but shows no mould or sour smell is still usable. Soak it in warm water for ten to fifteen minutes and it softens enough to blend into a paste for baking — brownies, energy bars, a sweetener swap in oatmeal. This is the standard move in commercial kitchens that buy dates by the case and can't afford to waste stock between deliveries.
What actually needs to go in the bin is anything with visible mould, a fermented or alcohol-like smell, or a sticky white bloom that doesn't wipe off (that's usually just natural sugar crystallising, but if it's paired with a bad smell, don't risk it). Cutting around a mouldy spot doesn't work on dried fruit the way it does on a loaf of bread — the mould has usually already spread through the flesh.
Buying in the right quantity in the first place avoids most of this. A household eating dates a few times a week does fine with a 1kg to 2kg bag bought every few weeks rather than a bulk box that sits half-finished. If you're weighing up which grade to buy, the Medjool pricing breakdown is worth reading first, and the piece on fresh versus dried dates covers which form keeps longer in a home pantry. For sourcing decisions at larger volumes, what to check with a dates supplier is a useful next read.