[LINK] Re: Heads Up - troubles with time zones

[Stilgherrian]

On 29/3/06 4:03 PM, "Rick Welykochy" <rick at praxis.com.au> wrote:
>>     http://en.wikipedia.org/wiki/Daylight_saving_time#Microsoft_Windows
> 
> Interesting read. As often the case, Microsoft has ignored years
> of practical experience gleaned from Unix and other systems and
> implemented it incorrectly.
> 
> Since Windows systems have only one DST entry per time zone, which
> must be applied uniformly across all years, time references to
> dates in exceptional DST years (like the Sydney 2000 Olympics)
> will be wrong during the DST period of exception in that year.
> 
> For example, any datestamps correctly created in the period 27.08.2000
> to 28.09.2000 will be reported as one hour later by Windows software.
> This is because Windows will now have "forgotten" the exceptional
> DST date range for the 2000 Olympics. Some enterprise system!

Microsoft's writing on this seems to only look forward: it's all about
making appointments for the future. But calendar applications are also used
to keep a record of what happened in the past -- and this bug means those
records cannot be relied upon.

The problem isn't restricted to Windows. Entourage (Microsoft's equivalent
to Outlook, but for Mac) seems to use its own time zone code, not the
underlying OS X code -- presumably so it's interoperable with Exchange
servers, though maybe it's just because Microsoft seem not to have heard
about code re-use.

"Some enterprise system!" is the right reaction. The message is very clear:
you can use Outlook/Entourage/Exchange as a replacement for a paper diary,
but if you want to construct any kind of accurate recording system, look
elsewhere.

Actually, you can't even use it as a paper replacement, because at least
with a paper diary once you write "Monday 10am" it STAYS there -- it doesn't
suddenly become 9am later.

This is exactly the sort of thing I mentioned when I blogged about this
issue the other day.

    http://www.stilgherrian.com/business/daylight_saving_chaos_1/

And it *does* matter. In a previous business, a vehicle was clocked by a
speed camera, and our calendaring system told us which employee was using
the vehicle at that time.

A shame that nothing will improve as a result of all this. People will still
accept the flawed system with a shrug...

Stil


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