Since the series began, Nintendo has been coy on whether there's an official timeline for The Legend of Zelda. They've said there is one, locked away in Nintendo HQ, but the fact it's never been shared - and that each game seems so wildly different from the rest - has long clouded the topic.
Until now. Maybe.
And, according to one such person posting online (and helpfully translated by reader littsu), it reads like this. Note that the "split" is due to Ocarina's time differences and assumptions based on the different ways that story could have ended and branched off from his two ages: the Link to the Past split is Link failing, the Majora's split is Link defeating Ganon and branching off from his boyhood and the Wind Waker split is Link defeating Ganon and branching from his older years.
So, yeah, that suggests not only alternate universes, but two parallel universes spinning off the same single outcome.
Be warned: there may be errors, given the nature of the transcribing, and Nintendo may later own up and say this isn't the super-secret official timeline they've been guarding with their lives for decades. This may be just an "interpretation". Or something. Got that? OK, read on!
(네타) 완전히 밝혀진 젤다 타임라인 (하이랄 히스토리아) [Ruliweb]