[tz] Timezone in Brazil

Guy Harris guy at alum.mit.edu
Sun Oct 11 16:19:50 UTC 2015

On Oct 11, 2015, at 4:17 AM, Lester Caine <lester at lsces.co.uk> wrote:

> On 11/10/15 04:00, Guy Harris wrote:
>> But if you're stuck with presenting a list of "time zones" from which to select, that might require yet another database.  I'm not sure whether that'd be in the scope of the tzdb or the CLDR or neither of them - and for some locations, the appropriate tzdb zone might not really have a good name, other than what it's called now or "XXX time" if it's shuffled between differently named zones or is one of those "XXX time except that we don't do DST" zones.
> The basic fact is that tz provides a limited set of generic rules. In
> hindsight this may have been better identified as a simple numeric ID?

Or alphanumeric - anything to keep UI developers from "cheaping out" and, in the tzdb zone selection UI just displaying tzids or slightly-tweaked tzids (e.g., turning underscores into spaces, which wouldn't really make the UI much better; for example, offering "Los Angeles" as the choice for everybody on the US West Coast isn't much of an improvement over "America/Los_Angeles"), with the result that people complain here that the tzids mention the "wrong" city.

> That these rules ONLY apply to time data later than 1970 sweeps the
> problem of identifying just were some places were located earlier than
> that under the carpet,

I think that's the intent - to keep it out of scope of the tzdb.  As Paul has noted, the further we go back in time, the harder it is to find *correct* time zone information.  Go back far enough, and there *is* no standard time, and the "tzid" would end up being a longitude+latitude and you'd just calculate local time from that.

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