On 5 September 2013 15:08, Stephen Colebourne <scolebourne@joda.org> wrote:
On 5 September 2013 13:55, Paul Eggert <eggert@cs.ucla.edu> wrote: Its important not to forget the existence of non zic parsers here. Adding lots of new data to the current set of files would impact them, forcing them to use all the new IDs or implement their own winnowing.
Whereas if the additional zones were placed in a new file "extended", then zic and non-zic consumers could easily choose whether to include the extra data or not.
None of the above should stop existing Zone and Link entries from being expanded with researched historic data. ie. pre-1970 data for the existing set of IDs should remain in the main files, unless an entirely new data format is being created (which I'm not enthused about).
Just to outline my needs from the dataset: - the full time-zone history for all IDs currently in the "main" files - the old IDs located in the "backward" file The current way of working appears to be is: - the full time-zone history for all Zones currently in the "main" files - no time-zone history for Links currently in the "main" files - the old IDs located in the "backward" file Note that the only IDs I need are those IDs that are currently deemed important enough to be in the current tzdb. I don't need any more IDs, or any more accurate history for locations (such as the difference between Paris and Lyon). I do need full history, if available, for IDs currently defined as Link entries. The discussion is proposing a variety of extensions and file format changes, but to actually achieve the minimal extension outlined above will require parsing and understanding the full set of extended data. My preferred solution would be to allow Link entries to be converted to Zone entries if and when the history becomes available. With a winnowing solution, this would have no impact on data sizes or performance AFAICT. Summary, there is a middle ground between not caring about pre-1970 and caring about everything. I don't want the need for that middle ground to be lost. Stephen