Here are some other thoughts about any potential IANA effort in this area: * As others have mentioned, the effort should address authentication of the timezone data. It would be helpful to have a real authentication expert in on this, since we want something simple and scalable and workable downstream (see below). * Each tzdb release comes with a version number like "2019b", development commits have version numbers like "2019b-11-gd8c6bf2". Downstream publishers often make minor changes to the data, and some append a suffix to the version number to indicate this. The mechanism for publishing this number is specified only loosely in Internet RFC 7808 section 3.10, and presumably the IANA effort would do something more specific. Downstream modifications will complicate data authentication. * Each tzdb release has auxiliary metadata files zone1970.tab and iso3166.tab that contain vague geographical information associated with each tzdb entry. (In some cases this vagueness is intentional, to avoid running into political disputes.) These files are not covered by TZDIST but some POSIX-style clients use them. How should metadata like this be addressed? * Each tzdb release has an auxiliary data file 'leapseconds' that is widely used by clients running NTP and related software. TZDIST has a "leapseconds" action that conveys the information in a different format, and we would need to make sure that this all hooks up correctly. * It'd be helpful to support not only TZDIST, but also a reasonably simple protocol, presumably based on HTTPS transfer of the data since HTTPS is widely supported. This could be used by platforms that don't support TZDIST, or that need auxiliary metadata that is outside the scope of TZDIST. For example, many NTP hosts need a 'leapseconds' file but don't support TZDIST or grok its leap seconds data format.