I took a trip to the UK last week, and as an avid Coke Zero drinker, was surprised to find that my Coke Zero supposedly expired in March 2016 in most places I went.
Surprised, because in the US, diet sodas are typically dated 3-4 months from production, and actually do taste noticeably less sweet at that point (to the point that some brands of soda, including Coke Zero, are undrinkable for me if they're at the expiration date). March 2016, even assuming they were produced next door and stocked that day, was almost 6 months out, and considering about 75% of the sodas I found were that date (I did see some Jan and Dec, but almost all Mar) it sounds like they're dated at least six months out. But even the Dec dated sodas tasted fine (Which, if they were 3 months old, would start tasting off to me normally in the US).
Why is that? Does the UK have different regulations, or are there different formulas that explain it, or different storage, or ... something else? The base sweeteners were the same (Aspartame and Ace-K), though of course it's impossible to tell %s in the US so who knows if they're the same; and I think it all tasted differently there than in the US, so it's hard to say if there's more/less in there.