Technically windows does not use GMT (working out the time by looking at
stars etc). It uses UTC which is atomic clocks. The label of the time
changes with Daylight Saving. Windows does not use the label except in some
americian time zones. We just changed from AEDT to AEST.
"pbx" <pbeisel@gmail.com> wrote in message
news:1175112743.763933.149210@e65g2000hsc.googlegroups.com...
> On Mar 28, 10:57 am, "Tom Porterfield" <tppor...@mvps.org> wrote:
>> pbx wrote:
>> > Vista seems confused about what GMT is:
>>
>> > my date/time is 3/27/2007 5:14PM in GMT -8 Pacific Time (US & Canada)
>>
>> > if I set the additional clock to both available GMTs:
>>
>> > GMT (Greenwich Mean Time: Dublin, Edinburgh, Lisbon, London)
>> > and
>> > GMT (Casablanca, Monrovia, Reykjavik)
>>
>> > the first one (london) says its: 3/28/2007 1:14AM
>>
>> > the second one (casablanca) says its: 3/28/2007 12:14AM
>>
>> > the second one is right!
>>
>> Actually they are both right but you have to understand what you are
>> seeing.
>> Pacific Time (GMT-8) is currently in daylight savings time meaning you
>> are
>> actually currently GMT-7. True GMT (Greenwich Mean Time) does not have a
>> concept of daylight savings time so GMT-8 is always GMT-8 even if when
>> adjusted it is GMT-7. Casablanca is not true GMT and while Casablanca
>> does
>> not change its clock for daylight savings time, any conversion from local
>> time where DST is in effect does need to be accounted for and Windows
>> does
>> this automacitally for you. To see the correct time for true Greenwich
>> Mean
>> Time you need to set that as your timezone AND disable the automatic
>> adjustment for daylight savings time.
>> --
>> Tom Porterfield- Hide quoted text -
>>
>> - Show quoted text -
>
> Tom--
>
> that's a pretty good explanation but...
>
> are saying that GMT is now +1 in London because London "sprang
> forward" to summer time.
>
> but then is:
>
> http://wwp.greenwichmeantime.com/
>
> wrong?
>
> is there no absolute concept of GMT? http://wwp.greenwichmeantime.com/
> matches the Casablanca setting.
> Also the .NET Framework 2.0 (DateTime.UtcNow) running on the same
> Vista machine reports GMT to match the Casablanca setting.
>
> seems to me that GMT is GMT and London is now +1 GMT... so if the
> Vista setting was London it would be correct... but it starts off
> saying that its GMT (or is GMT <> UTC?)
>
> chime in all (pun intended).
>
>
>