Microsoft exec says Namibia and Iran have recently changed DSTrules

Jesper Norgaard Welen jnorgard at
Mon Mar 5 20:48:14 UTC 2007

John Gray, thanks for the quick feedback.

Concerning problems in 2009 I think that many people loading the timezone
updates in 2007 will not do so in 2009 if there were no actual rule changes
since - so I recommend getting it right now.

Namibia: I must admit I had not seen the -1.00 in Daylight Bias:

My first comment is: this will work technically, as you claim! But is it the
best way to do it? Actually "hora de verano de Namibia" means "summertime of
Namibia", which will apply between April and September. Note that this use
of summertime/wintertime is opposite to all other countries (I think) and
also to the web links you sent. However, when you look it up in the list,
all other countries are also listed for their wintertime, the GMT offset
when not applying DST. Putting Windhoek as (GMT+02:00) is therefore a bit
like reporting the revenue of 250 companies before tax, and 1 company after
tax - it is just impractical for most purposes. Therefore if you want to
call the period something different, for instance calling it summertime
between April and September, better do the change only in the Abbreviations,
so that Time Zone Name is (GMT+01:00) Windhoek, Abbreviation(1) is "Namibia
summertime", Offset from GMT is +1:00, Start Day and Last Day are inversed,
Daylight Bias is +1:00 and Abbreviation(2) is "Namibia wintertime". This
will confuse less people, I think.
- Jesper Nørgaard Welen

>-----Original Message-----
>From: John Gray [mailto:johngray at]
>Sent: Domingo, 04 de Marzo de 2007 20:23
>To: Jesper Norgaard Welen
>Subject: RE: Microsoft exec says Namibia and Iran have recently changed

>Jesper, thanks for the info.  Yes, we have been working very hard to get
this all in place and still have a long way to go for some issues.

>It looks like we may have a minor issue for 2009 but we should be able to
address it with a custom set for that year.  I've forwarded your
observations to the people that own the >detailed specifics of our DST data
for Windows.

>For Namibia, oddly enough we have an internal email on file confirming this
is the official preference of the government - note that we have a "-1 hour"
offset for the DST period so the clocks and offsets will be correct, it is
just the name that is in dispute (e.g. which period of the year to call
"daylight saving"). From some of their websites, it looks like they simply
use "summer time" and "winter time" without referring to either one as a
"saving" time per-se.  It is also entirely possible different organizations
within their government may have different preferences here.


>For Chile, yes I am aware we worked hard to get it right.  Apparently their
official documents defined the change to happen at "24:00" hours, which
never actually occurs (I'm not sure if they ever fixed this).  A classic
case of we know what they meant, but causes us to do strange things in the
digital world.

>For the rest I'll have to wait for the experts to investigate.

>Thanks again,

>John Gray
>Director, Windows Sustainability Engineering Services

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