glee, please come back and post ASAP so we know you are OK!
My mantra: when in doubt, throw it out (no matter what date is stamped on the container).
Username/Post combo of the day (irony category)
To be clear, “looks OK” also means checking for things like bulging cans. And I was assuming packaged commercial food, but if you know something’s history, that’s relevant too. Yeah, ultimately, there’s no guarantee of detecting dangerous spoilage no matter what you do, but the use-by date doesn’t really add any significant amount of useful information: A food can smell and look OK and still be dangerous, but then, it can also smell and look OK and be before the use-by date and still be dangerous.
To tell the truth, I thought I was being whooshed and went along with it, as it’s been a long time since I’ve had a good whooshing. 
Milk can also be good for up to a week past its “best by” date. And by good, I mean it still tastes fresh, hasn’t any clumps, and doesn’t smell odd. I’ve used milk ten days past its date, and it still was fine.
Expiration dates are based on performed stability studies; an expiration date cannot exceed a time frame established by actual or accelerated stability data.
Admittedly, I’m not certain about the exact rules for “use by” dates.
Once a manufacturer has established an expiration/sell by/use by date acceptable to distributors, retailers, and regulatory agencies, they have little or no incentive to extend the dates with additional studies.
However, I worked at a donated food distribution warehouse, and the rule was, as long as it’s not open, send it out and let the cook decide.*
I’m decently well off, so if I have any doubt about food, I cook it up for the dogs, compost it, or donate it, as appropriate.
(We go through all the pantry food and donate every thing hitting ‘use by’ soon to a food pantry every Thanksgiving. We probably donate about half of our “pantry” processed food.)
If you see a time alongside a use by date, it’s probably there to serve as a production batch identifier - useful if the factory needs to recall product, or if QC rejects it after it leaves the belt, but before it goes out of the door.
They actually have several incentives to under-estimate the longevity of the food - if you throw it away, you might buy another; if the supermarket throws it away, they will buy more to restock, and if they err significantly on the side of caution with the dates, the risk of complaint is reduced.
Given that it’s going to be cooked as well I’d have no qualms about it. Cook it on full power for the instructed time and maybe a little more, and I doubt if you’re just warming up any nasties. And if it turns out you were, then as long as your health isn’t already compromised in some way (in which case, play it safe), the results may be unpleasant but unlikely to be dangerous - most likely a case of better out than in, and chalk it up to experience.
Thanks for all the replies.
I decided in the end not to risk a stomach upset with many delicious Xmas meals on the horizon, but it was helpful to hear from you.
I don’t like wasting food, so I think I’ll buy more cans. They have lengthy expiry dates.
This is bad advice. Cooking does not destroy the toxins produced by some foodborne pathogens - in particular, this product contains rice, which is a case in point.
Eggs have a reputation for being highly perishable, but really, it’s extremely difficult for eggs to go bad. Refrigerated, they’ll last for many months. Even with no refrigeration at all, they’re good for weeks. The only reason they have such a reputation is that, in the rare event that they do go bad, they go very, very bad. But that’s actually another argument for their safety: If you don’t know if an egg is bad or not, then it’s good, because if it were bad, you would know it without any ambiguity.
^ You must be the Egg Man.
Adam Ruins Everything.
How sure are you that that doesn’t mean the use by date is “Dec 2016”, IOW a year ago rather than 4 days ago?
I take a middle of road position on these dates.
Many of them are exaggerated or are intended to push retailers to get old stock off the shelves (sell by dates).
As a matter of science, some particular packaged food isn’t known perfectly healthy on Day X umpteen days after manufacture, and known deadly on Day X+1. But typical packaged food is also not safe after 50 years. And for darn sure packaged food can become deadly bad with no off smell or taste.
So with all that, where should we each draw our lines?
Don’t “use by” dates typically include the year? So it would say “16 Dec '17” or something similar.
A lot of packaged foods are, in fact, safe even after 50 years. In particular, anything properly canned will remain good until and unless the can rusts through.
Maybe this one does, maybe it doesn’t. maybe the OP read it right and maybe he/she didn’t.
It seems highly illogical to question the safety of something just 4 days after the date. That might have been a sensible question 25 years ago when these dates first began appearing on most goods. Otherwise I wonder what rock this person just climbed out from under. Hence my question for more/better details.