Proposal: API for thread-safe time zone functions

Jonathan Lennox lennox at
Fri Jun 8 15:02:08 UTC 2001

On Friday, June 8 2001, "Clive D.W. Feather" wrote to "Jonathan Lennox, tz at" saying:

> Jonathan Lennox said:
> > One of the major shortcomings of the current time zone API defined by ISO C
> [...]
> > Therefore, I've written up a proposal (attached) for a thread-safe API for
> > time zone functions.
> Please don't.
> There are a number of known deficiencies with the C time stuff, and it
> really needs redesigning from scratch with a solid set of concepts behind
> it. For various reasons I'm supposed to be organising a group to do that,
> but it's way way down my list of priorities.
> Any new design will, of course, need to address these issues, but I don't
> think there's any point in doing this sort of ad hoc work to solve just one
> item.

Well, this is the thing.

I need C-based thread-safe time zone functions for a project I'm working
on.  I figured a) I'd base my code on tzcode, b) it'd be sensible to
contribute my modifications back to tzcode, and c) it'd be good to have a
sensible API for my code.

I don't have the time or experience to do a full re-write of the C time
stuff, though.

I've tried to model my (revised) API (to be sent out to the list shortly) on
a subset and simplification of Markus Kuhn's proposed time zone model, to
keep upward extensibility to a full, sensible API.

Given that I need to write this code anyway, I don't see any benefit (to me
or the community) from keeping it private.

Jonathan Lennox
lennox at

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