On 5/15/20 7:39 AM, Paul Ganssle wrote:
I'd say one could easily want:
1. Every valid value for key that doesn't raise an error when you call ZoneInfo(key)
Does ZoneInfo operate by looking for an actual file, or by setting TZ='key' and seeing whether that works? If the latter, there are many keys that are not listed anywhere because they're specified by POSIX. A simple example is TZ='MST7' which is a valid POSIX key and which is commonly used, but for which there is no file or tzdata.zi entry. I looked at PEP 615 and didn't see any mention of the issue of POSIX-specified TZ settings.
I'm still mildly uncertain as to whether it's possible that tzdata.zi might have more zones than are actually installed (for example if a distro doesn't install anything in backward or antarctica for some reason).
In the reference implementation, the zones are installed from tzdata.zi so the lists should be identical there.
Is it always the case that the right/ and posix/ trees are identical to the primary tree?
Yes, in the reference implementation.