[tz] uptodate data

[Paul Eggert]

On 11/9/19 3:51 AM, Jean via tz wrote:
> There are other problems, like the America/Chicago timezone which is 
> notorious for giving false results for years before 1970

Although Matt addressed your other points, I'm curious about this one. 
In what sense is tzdb's America/Chicago "notorious" for being wrong? I 
used Google to search for '"America/Chicago" false results' and the only 
hits I came up with were downstream bugs (e.g., in PHP installation, or 
in mistaken use of Python primitives), not bugs in tzdb itself.