Okay, so you found a bag with a roast date that fits the window. Does that guarantee a great cup? Not quite. A few things can throw your benchmark off:

• Storage conditions: If the shop stored the beans in a sunny window or a warm warehouse, freshness degrades faster. You can't control that, but you can ask.
• Grind size and brewing method: A coarse grind in a French press extracts differently than a fine espresso grind. Your taste buds might prefer one over the other, regardless of roast date.
• Bean origin and roast profile: A light roast from Ethiopia tastes different from a dark roast from Sumatra, even when both are fresh. Don't judge a coffee solely on the date.
• Pre-ground vs. whole bean: Once you grind, the clock speeds up. Ground coffee loses flavor within minutes, not weeks. If you can, buy whole beans and grind at home or at the shop.

So, the roast date is a necessary condition for good coffee, but it's not sufficient. You still need decent beans and a method that works for you.