Article View: borland.public.cppbuilder.nativeapi
Article #5742Re: Datetime conversion between timezones
From: Dennis Jones
Date: Fri, 08 Jul 2005 21:03
Date: Fri, 08 Jul 2005 21:03
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"Dennis Jones" <nospam@nospam.com> wrote in message news:42cec603$1@newsgroups.borland.com... > Hi, > > So, I have two questions: > > 1) How does one get timezone information about OTHER timezones? > 2) Assuming it is possible to get the source/target timezone information, > what do you do when you are running on an OS that doesn't have > TzSpecificLocalTimeToSystemTime? I found my own answers: 1) HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\TimeZones 2) Source code from WINE But a new problem arises: Several timezones have the same offset from UTC, but have differing rules for dealing with standard/daylight times. So, if your sole piece of information about a timezone is its offset from UTC, you have an ambiguity for which there is no resolution. For instance, if you have -0700, there is no way to know if that refers to Mountain Standard Time (which adjusts for daylight savings) or US Mountain Standard Time (Arizona, which does not adjust for daylight savings). Sigh. - Dennis
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X-Google-Thread: 10cc67,424ca78a9d71afb X-Google-Attributes: gid10cc67,public X-Google-Language: ENGLISH,ASCII-7-bit From: "Dennis Jones" <nospam@nospam.com> Newsgroups: borland.public.cppbuilder.nativeapi References: <42cec603$1@newsgroups.borland.com> Subject: Re: Datetime conversion between timezones Date: Fri, 8 Jul 2005 14:03:06 -0700 Lines: 30 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 NNTP-Posting-Host: 204.200.27.7 Message-ID: <42ceea0d@newsgroups.borland.com> X-Trace: newsgroups.borland.com 1120856589 204.200.27.7 (8 Jul 2005 14:03:09 -0700) Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!news.glorb.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!atl-c02.usenetserver.com!atl-c07.usenetserver.com!news-out.nntp.be!propagator2-sterling.newsfeeds.com!in.nntp.be!caladan.landsraad.net!newsgroups.borland.com!not-for-mail