[tz] [musl] Re: Weird PST8PDT and EST5EDT behavior on Alpine Linux

[Guy Harris]

On Mar 5, 2024, at 12:56 PM, Russ Allbery via tz <tz at iana.org> wrote:

> but for the record, PST8PDT was for support for very
> old commercial UNIXes where I believe that was the only recognized style
> of TZ setting, and I'm pretty dubious that the POSIX-introduced :PST8PDT
> syntax would work there.

That TZ syntax dates back at least to System III:

	http://www.bitsavers.org/pdf/att/unix/System_III/UNIX_Users_Manual_Release_3_Jun80.pdf

(see CTIME(3C)), which did not support anything tzdb-related, and didn't even support the more elaborate POSIX TZ syntax to include rules.  At least according to the CTIME(3C) page, System V Release 1 doesn't appear to support the POSIX syntax (or tzdb), and the same is true of SVR2 and SVR3.

Full POSIX support - but not tzdb support, may have shown up in SVR3.2; SVR4 had a tzcode-based implementation and shipped with the tzdb files.