Robert Elz via tz <tz@iana.org> writes:
If you want to claim some data is incorrect, provide evidence to support that, otherwise you're simply maligning whoever supplied the data in the first place (nb: not necessarily the person who edited it into tzdb, but the source of their information.)
Yeah, that is a fair point. It looks like a lot of the stuff that initially got put into backzone was put there because the only source for it was Shanks, and we've found enough errors in Shanks to have healthy distrust for it. Still, in the absence of other evidence, that remains the best available data.
... That way the data might be corrected. But not if it is buried in backzone.
After thinking about this for awhile, I think that a lot of our problems can be summarized as "backzone is misdesigned". Having links in the base dataset that are overwritten by more-extensive information if you enable backzone is just an awful design, because it's got next-door-to-zero discoverability. End users cannot tell if they have the best available info or a lie, unless they understand enough about TZif to look into that file tree --- and unless it's set up using symlinks, which seems to be distinctly a minority practice, even that won't make it very clear. As a modest proposal, therefore, I suggest that we should consider just dropping all the overwritable links. That way, if you have a base dataset, it will be obvious that Africa/Timbuktu is not good data because it won't be there at all. If you enable backzone (which perhaps needs a better name), then you get Africa/Timbuktu along with a ton of other data of perhaps dubious reliability. But you know what you have. The current design where the same zone identifier could refer to two different datasets is bad by any rational standard, and we've only gotten away with it because the field usage of backzone is negligible. But if we keep moving stuff to backzone, that's going to change. There's a separate question of what the rule should be for putting a given zone into the "base" or "extended" collections. But maybe that becomes less of a hill that people are ready to die on. If we do it this way, I foresee a lot of distros starting to ship the "extended" collection -- but they won't be shipping different definitions of the same zone name. regards, tom lane