Maybe a little too slick. Maybe a little too anthemic. Maybe a little too comfortable. Maybe a little too familiar. Maybe even a little out-of-character for The Offspring, one of the heroes of 90's punk revival, whose music was characterized by smart-assery (on "Self Esteem" and "Pretty Fly For A White Guy") balanced with just the right flavour of sincerity (on "The Kids Aren't All Right" or "Gone Away.") "Days Go By" might seem like the work of too many other bands, but not sounding the same as any other Offspring song doesn't mean this isn't a good version of this song. It's the sort of general "good feeling, put the past behind you" that a band has the right to record after a few decades, and bless 'em if they do it this good.
Offspring aren't a young, dangerous band anymore and my recollection of their last set, Rise & Fall, Rage & Grace, was that their old sound just didn't have the same verve. Dexter Holland is now in his mid-40s. He can still rock, but he maybe can't be a California punk brat joking about chicks with issues and mooching girlfriends. Shifting into that higher-octane, arena-ready (and Top 40-amenable) sound seems to be working. I can believe this song is the work of a band that has been around for 20 years, more than I would believe in another "Original Prankster" or "Hit That." There's no blueprint for how a band is supposed to age, but the sooner they recorded this song, the better.