Microsoft KB Archive/932305

= FIX: Visual C++ .NET 2002 C runtime daylight saving time 2007 update for the TZ environment variable problem =

Article ID: 932305

Article Last Modified on 4/13/2007

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APPLIES TO


 * Microsoft Visual C++ .NET 2002 Standard Edition

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SYMPTOMS
The U.S. Energy Policy Act of 2005, passed by the U.S. Congress in July of 2005, extended daylight saving time (DST) in the United States by approximately four weeks. Beginning in 2007, DST starts three weeks earlier, on the second Sunday in March at 2:00 AM. In 2007, DST starts on March 11. DST ends one week later, on the first Sunday of November at 2:00 AM. In 2007, DST ends on November 4.

In Microsoft Visual C++ .NET 2002, some C runtime (CRT) functions ignore the daylight saving time (DST) rules that are set in the operating system when the TZ environment variable is set. For example, the localtime and _localtime64 functions identify the first Sunday of April and the last Sunday of October as the start dates and the end dates for DST. Therefore, a Visual C++ .NET 2002 application that uses the TZ environment variable may not work as expected.



Hotfix information
A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Visual C++ .NET 2002 service pack that contains this hotfix.

To download the hotfix directly, visit the following Microsoft Web site:

http://go.microsoft.com/fwlink/?linkid=87459

Prerequisites
You must have Microsoft Visual C++ .NET 2002 Service Pack 1 (SP1) installed to apply this hotfix.

Restart requirement
You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
After you apply this hotfix, DST starts on the second Sunday of March and ends on the first Sunday of November in 2007 when you use the TZ environment variable. In 2006 and in earlier years, DST starts on the first Sunday of April and ends on the last Sunday of October.

The following CRT and Microsoft Foundation Classes (MFC) functions call the localtime and _localtime64 functions and may also be affected by this issue:
 * ctime
 * _wctime
 * _tctime
 * _ctime64
 * _wctime64
 * _tctime64
 * mktime
 * _mktime64
 * _utime
 * _wutime
 * _tutime
 * _utime64
 * _wutime64
 * _tutime64
 * COleDateTime::operator-
 * CTime::GetLocalTm
 * CTime::Format

