Timezone Rules, which dataset to pick?

Hi! As you might be aware, I maintain the date time support in PHP. As part of that I regularly have to update the rules that timezones employ - changes in Daylight Saving Time rules, or other changes to rules due to political foibles. In the last few years, the maintainer of the Iana TZ Data project has diverged somewhat from the consensus of the community, and degraded some data by no longer having an entry for each country and merged timezones where data does not differ since 1970. (Removing transitions from these regions where data **does** differ before 1970, even if these were available). Java's date/time maintainer has created a fork based on the original Iana TZ data to put back some of the removed/deprecated data to better serve their users, and I would think that this is also best suited as a data set for PHP. If you want to read about the intricacies, see: https://github.com/JodaOrg/global-tz#rationale But this does mean a divergence from the "official" TZ data, although Joda's data is arguably better. My recommendation is that from the 2022b release we switch to Joda's version. (I will today merge in the 2022a data from the Iana source.) Comments? If you want to discuss this live, come find me in "Room 11": https://chat.stackoverflow.com/rooms/11/php cheers, Derick -- PHP 7.4 Release Manager Host of PHP Internals News: https://phpinternals.news Like Xdebug? Consider supporting me: https://xdebug.org/support https://derickrethans.nl | https://xdebug.org | https://dram.io twitter: @derickr and @xdebug