[I am cc'ing this to the tz mailing list (and changing the subject line) to give tz readers a heads-up about the terminology issue. The question here is: should tzdb man pages say "time zone" or "timezone"? For context please see Michael Kerrisk's email <https://marc.info/?m=152964652828320>, which says:
When I inherited the project, the pages used a mixture of "time zone" and "timezone", with the former predominant. I nevertheless standardized on the latter, and although I don't recall for sure, I suspect it was because that is the spelling used in POSIX. (As an aside, there's an argument that--because POSIX--tzdb might want to consider switching spellings.) I'm not religious about the particular choice (although I have naturally now got used to the particular choice I made some years ago), but I did make that choice because I want consistency within the project, and I'm reluctant to introduce inconsistency.
and my response <https://marc.info/?m=152964676331902>, which says:
I deferred to POSIX for "timestamp" versus "time stamp", but "timezone" is a bridge too far for me.
] On second thought, perhaps I was too hasty. We could distinguish "time zone" in the usual English-language sense (a set of geographic locations that currently share the same standard time offset from UTC) from "timezone" in the POSIX sense (a history and predicted future of UTC offsets, abbreviations and isdst flags). If so, the tzdb documentation could be more careful about using "time zone" for the former and "timezone" for the latter, and this would make for fewer changes to the GNU/Linux man-pages for tzdb. I can look into this and propose an updated set of tzdb-related patches accordingly. If I were designing the terminology from scratch, I wouldn't specify two nearly-identical phrases "time zone" and "timezone" to mean such different things. However, the phrases do have the advantage of existing practice (common English usage and POSIX, respectively).