On 2020-05-15 13:52, Paul Eggert wrote:
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.
For every zone in the sources, try the following from your tzdata directory: $ awk ' /^Zone/ { print $2, "Zone", FILENAME } /^Link/ { print $3, "Link", FILENAME, $2 } /^[^#]/ && FILENAME ~ /zone[^.]*\.tab/ { print $3, "Tab", FILENAME, $1, $2 } ' africa antarctica asia australasia backward backzone etcetera \ europe factory northamerica pacificnew solar8[7-9] systemv \ usno1988 usno1989 usno1989a usno199[578] zone.tab zone1970.tab | \ sort -dfuk1,1 you can drop the sort -u or the sort command to see the selected data, or drop the extra fields to just get the zone names - 586 unique entries total possible. If I missed some selection source or criterion please post on the list. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in IEC units and prefixes, physical quantities in SI.]