`zipfile`: docs should document what `ZipInfo.date_time` actually is

Documentation

Currently, the documentation for ZipInfo.date_time is:

The time and date of the last modification to the archive member. This is a tuple of six values:
...
Note: The ZIP file format does not support timestamps before 1980.

This should be extended/clarified to define which date/time is meant (which currently is only hinted by the does not support timestamps before 1980.

The ZIP format supports for multiple timestamps:

• there's the last mod file time and last mod file date in the central directory (see chapters 4.3.7 and 4.4.6)
• but also various times (e.g. for NTFS and UNIX) as part of the extra fields (see e.g. chapter 4.5.7).

The latter may e.g. support times before 1980, higher resolutions and time zones.

Right now it seems not strictly defined what .date_time actually returns - from what I can see from the code, it's the one from the central directory - but that could in principle be just an implementation detail and a future version of zipfile could e.g. use the extra fields if present.

Thus it would be nice, if the documentation could specify, whether .date_time is always meant to be the time from the central directory, or whether this could change.

Thanks,
Chris.

Linked PRs

• gh-136082
• gh-138076
• gh-138077

从链接的 zipfile.ZipInfo.date_time 文档开始，检查提供此属性的现有 zipfile 实现。更新文档，说明它表示哪个 ZIP 时间戳，以及它与其他时间戳字段的关系，然后验证渲染后的措辞和文档检查。