Why would there be two files labeled 2015g? You mean in the even that someone modified the IANA tzfile before running it through zic? I think if you make it so the included version number comes from the makefile, people could be made aware that they should modify their versioning if they are worried about this occurrence. In my mind, as long as the default case (pulling IANA tzdata down and running it through zic) produces something reliably versioned, the feature would be more useful than not. That said, as an alternative, maybe the METADATA file could also include a version and a CRC-32 or an MD5 of the tzdata input, as an additional check for people who want to know that the inputs were actually the same. This might be overkill, though, because I don't totally understand the use case where multiple tzdata files are floating around with the same release number. On 10/25/2015 03:13 AM, Paul Eggert wrote:
Paul G wrote:
If not, I would like to suggest that a VERSION or METADATA file be added to the zoneinfo output.
Although there is a version number in those files, it's not what you're looking for: it's the version number of the zic format (a number that changes only very slowly), not the tzdata version number. There's no provision in the current zic format for storing an arbitrary tzdata version number like '2015g'. Perhaps we could add one, but there would be a downside: people might take strings like '2015g' too seriously, and assume that two files from different sources labeled '2015g' would be identical (an assumption that would not be true). This downside has made me reluctant to change the zic format in this area.