Is more detailed timezone history desired?

Paul Eggert eggert at CS.UCLA.EDU
Thu Mar 10 22:34:34 UTC 2005

Alois Treindl <alois at> writes:

> Because I read in the docu that the focus of tzdata is the post-1970
> time range, I have asked my question.

My focus has been on the post-1970 time range mainly because I didn't
have the resources to go back before that.  POSIX specifies a 1970
cutoff but it's pretty arbitrary.  In practice the vast majority of
POSIX systems support negative time stamps (for times before 1970), so
it would be nice to get things "right" on such hosts (for people who
prefer such things).

> The large majority of tzdata users might consider such historical detail
> data to be unnecessary noise, which just blows up the database volume
> and confuses the innocent Linux installer when a strange number of zones
> appears as a choice.

That could be addressed by separating the database into a
"post-1970-only" version (which is what we have now) and a "complete"
version (which would add new zones as needed for regions that differed
only before 1970).  If done right, it should be easy to derive the
former from the latter automatically.  Presumably most GNU/Linux users
would install only the former.  For compatible naming we could call
the former "tz" and the latter "tz-complete", or something like that.

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