[tz] Preparing to fork tzdb

[Guy Harris]

On Sep 22, 2021, at 5:03 PM, Howard Hinnant <howard.hinnant at gmail.com> wrote:

> On Sep 22, 2021, at 8:00 PM, Guy Harris <gharris at sonic.net> wrote:
>> 
>> On Sep 22, 2021, at 4:49 PM, Howard Hinnant via tz <tz at iana.org> wrote:
>> 
>>> I applaud the motivation to make these changes.  But is it really ethical to knowingly introduce incorrect information into the default configuration, where previously the information was correct?  Even if said information is “historic” or even “not officially supported”?
>> 
>> As per my mail, is the issue here that the Europe/Oslo information, for example, is believed to be correct, whereas the America/Montreal data, apparently moved to backzone in 2015, is *not* believed to be correct?
> 
> I believe we’re discussing 2021b, not 2015x.

I'm *mentioning* 2015c to indicate that it's not as if this is the first time we've moved something to backzone.

> If we made a mistake in 2015, we should fix it, not use it as a justification to make the same mistake again today.

That'a an "if".

I can see several views here on what should be done:

	"We should never move anything to backzone, we should never have moved anything to backzone, and we should not only not move Europe/Oslo to backzone now, we should undo all the moves we made to backzone."

	"We should never move anything to backzone, we should never have moved anything to backzone, but what's done is done, so we should not move Europe/Oslo to backzone but we should leave the existing stuff in backzone there and, perhaps, if it's either shown to be accurate or updated to be accurate, move it from backzone to the main database."

	"We should only move to backzone data we don't believe to be accurate, so we shouldn't move Europe/Oslo to backzone but we should leave the existing stuff in backzone there and, perhaps, if it's either shown to be accurate or updated to be accurate, move it from backzone to the main database."

	"We should move to backzone all zones that only differ prior to 1970."

There may be more.

(I don't hold any of those views at all firmly.  My personal preference for what to do in the short term is "put out 2021a plus fixes such as Samoa as 2021b, don't put out the results of the merger yet, and discuss this further to see which of those, if any, should be adopted as the new policy, or pick a policy that's not in the list if that's where we end up".)