On 02/20/2018 03:23 PM, John Hawkinson wrote:
Although it's not now clear what that other location would be (it'd depend on what part of the US switches), one candidate would be America/Indiana/Indianapolis. I'm pretty sure that's not a reasonable candidate:)
I can't tell if you're joking, but even if the rules in Theory happen to allow or recommend that choice, I'm pretty sure we would revise them to discourage choosing a candidate that has a history that is so radically divergant from the vast majority of the geographical area in the zone.
I was partly joking (because I think it unlikely), but partly not. As Guy Harris wrote, the whole idea of TZ='US/Eastern' is reasonably fuzzy and there's certainly no expectation of a particular time zone history for it. Because US/Eastern is intended for current and future timestamps for a "generic" location in the US Eastern time zone, it cannot be correct for all timestamps between 1970 and now. So, although we would keep a backward-compatibility link for US/Eastern even if New York City moved to the Atlantic time zone, there's no guarantee about which US city (if any) would be referred to by any new US/Eastern backward-compatibility link.