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

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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 available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

To download this hotfix from the MSDN Code Gallery, visit the following Microsoft Web site:

Note The MSDN Code Gallery displays the languages for which the hotfix is available. If you do not see your language listed, it is because the Code Gallery resource page is not available for that language.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:


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.
File nameFile versionFile sizeDateTime
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" 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
For more information about the TZ environment variable and the _tzset CRT function, visit the following Microsoft Developer Network (MSDN) Web site:For more information, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Article ID: 932305 - Last Review: 10/26/2013 07:39:00 - Revision: 4.0

Microsoft Visual C++ .NET 2002 Standard Edition

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