Brian Inglis wrote:
I suspect that right zoneinfo is not hugely important to the vast majority of tz users, but it is probably critical to those who do use it for their work, and updates will require work dealing with future times to be redone.
I doubt whether there are many practical end-user applications of this sort. The usages I've seen are regression testing and so forth, which need to deal with more-urgent tz updates anyway. Serious astronomical users must deal not only with leap seconds but also with a lot of other things, and I expect that they have longstanding procedures for this stuff in place and do not need or use tz's leap seconds. Any end users who need a tz-based leap-second table accurate months into the future have had to deal with this problem for many years, as we've been reasonably lackadaisical about generating new releases if the only reason was a leap-second that is months in the future. If this were a significant issue, it would be straightforward for a downstream distributor like Ubuntu or FreeBSD to use the latest leapseconds file from NIST or from GitHub. I don't know of any distributor who's done so.