jrl jrl at
Wed Feb 23 17:29:53 UTC 2011

Great visual... thanks Bill

From: Ian Abbott [abbotti at]
Sent: Wednesday, February 23, 2011 10:48 AM
To: tz at
Subject: Re: Macau

On 22/02/11 23:23, Bill Seymour wrote:
> I had trouble understanding this as well, so I wrote
> a little paper about it, mostly for my own benefit:
> I've mentioned it a couple of other times on this list,
> and nobody has corrected me yet. 8-)

Looks good.  It'd be great if this (or something like it) could be
distributed with tzcode.

> I think that much of the confusion is due to the rules
> wanting to be /both/ transitions (most of the rule) /and/
> steady states (the SAVE and LETTER columns).  I give
> an example in the paper.
> Zones are definitely steady states.  My understanding
> is that they're in effect during the half-open interval,
> [previous line's UNTIL, this line's UNTIL).  If there's
> no previous line, the lower bound is the beginning of
> time; for the last line, which has no UNTIL, the upper
> bound is the end of time. 8-)
> Does that make sense?
> --Bill

It makes sense to me.

-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti at>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-

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