Microsoft Windows-based applications that use the TZ environment variable may not work as expected because of changes to daylight saving time (DST). Starting in the spring of 2007, the DST start date and the DST end date for the United States will transition to comply with the Energy Policy Act of 2005. DST in the United States will start three weeks earlier (2:00 A.M. on the second Sunday in March) and will end one week later (2:00 A.M. on the first Sunday in November) than in previous years.
In Windows Vista, in Microsoft Windows Server 2003, and in Microsoft Windows XP, when you use the TZ environment variable, the C Run-Time (CRT) localtime function and the CRT _localtime64 function will not correctly recognize DST. These functions will recognize DST as starting on the first Sunday of April and as ending on the last Sunday of October for all dates.
Note If you have an application that uses the Microsoft C runtime (CRT) library, an update may be required. The recent updates for the CRT do not represent a newly discovered effect on products that were already listed in previous product-specific statements from Microsoft. However, the CRT updates are available for developers to update their applications.
If the CRT behavior affects an application, you can help resolve this behavior by installing the updated CRT library.
The CRT update and the Windows operating system update differ in the following ways:
•
The Windows operating system update enables Windows to recognize DST changes correctly by using the new DST rules for 2007. Microsoft generally recommends this update for every user.
•
When applications call CRT libraries after you install the CRT update, the CRT libraries use DST 2007 rules to handle dates correctly.
The CRT itself is not an application. A user does not directly interact with the CRT. Instead, the CRT is a DLL that custom applications use.
The cumulative Windows operating system update and the CRT update are unrelated. Neither update resolves a problem that is caused by the other.
To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
935791 (http://support.microsoft.com/kb/935791/) How to obtain the latest Windows Vista service pack
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 (http://support.microsoft.com/kb/119591/) How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
Prerequisites
There are no prerequisites to apply this software update.
Restart requirement
You must restart the computer after you apply this software update.
Update replacement information
This software update 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.
Windows XP
File name
File version
File size
Date
Time
Platform
Msvcrt.dll
7.0.2600.3085
343,040
19-Feb-2007
10:32
x86
Windows Vista, 32-bit version
File name
File version
File size
Date
Time
Platform
Msvcrt.dll
7.0.6000.20538
681,472
16-Feb-2007
02:42
x86
Windows Vista, 64-bit version
File name
File version
File size
Date
Time
Platform
Msvcrt.dll
7.0.6000.20538
641,024
16-Feb-2007
04:06
x64
Windows Server 2003, 32-bit version
File name
File version
File size
Date
Time
Platform
Msvcirt.dll
7.0.3790.652
51,200
03-Mar-2007
09:35
x86
Msvcrt.dll
7.0.3790.652
327,680
03-Mar-2007
09:35
x86
Windows Server 2003 Service Pack 1, 32-bit version
File name
File version
File size
Date
Time
Platform
SP requirement
Msvcirt.dll
7.0.3790.2893
56,832
03-Mar-2007
10:02
x86
SP1
Msvcrt.dll
7.0.3790.2893
349,184
03-Mar-2007
10:02
x86
SP1
Windows Server 2003 Service Pack 2, 32-bit version
File name
File version
File size
Date
Time
Platform
SP requirement
Msvcirt.dll
7.0.3790.4034
56,832
03-Mar-2007
09:47
x86
SP2
Msvcrt.dll
7.0.3790.4034
349,184
03-Mar-2007
09:47
x86
SP2
Windows Server 2003, 32-bit version
File name
File version
File size
Date
Time
Platform
Msvcirt.dll
7.0.3790.652
51,200
03-Mar-2007
09:35
x86
Msvcrt.dll
7.0.3790.652
327,680
03-Mar-2007
09:35
x86
Windows Server 2003 Service Pack 1, 64-bit version
File name
File version
File size
Date
Time
Platform
SP requirement
Msvcirt.dll
7.0.3790.2893
93,184
02-Mar-2007
18:27
x64
SP1
Msvcrt.dll
7.0.3790.2893
519,680
02-Mar-2007
18:27
x64
SP1
Windows Server 2003 Service Pack 2, 64-bit version
File name
File version
File size
Date
Time
Platform
SP requirement
Msvcirt.dll
7.0.3790.4034
93,184
02-Mar-2007
18:30
x64
SP2
Msvcrt.dll
7.0.3790.4034
519,680
02-Mar-2007
18:30
x64
SP2
Windows Server 2003, 64-bit version for Itanium processors
File name
File version
File size
Date
Time
Platform
Msvcirt.dll
7.0.3790.652
165,376
02-Mar-2007
18:27
IA-64
Msvcrt.dll
7.0.3790.652
894,976
02-Mar-2007
18:27
IA-64
Windows Server 2003 Sevice Pack 1, 64-bit version for Itanium processors
File name
File version
File size
Date
Time
Platform
Msvcirt.dll
7.0.3790.2893
184,320
02-Mar-2007
18:27
IA-64
Msvcrt.dll
7.0.3790.2893
952,832
02-Mar-2007
18:27
IA-64
Windows Server 2003 Service Pack 2, 64-bit version for Itanium processors
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Vista Service Pack 1.
CRT functions and Microsoft Foundation Classes (MFC) functions that call the localtime function and the _localtime64 function may also be affected by the DST change.
The following CRT functions and MFC functions call the localtime function and the _localtime64 function:
•
ctime
•
_wctime
•
_tctime
•
_ctime64
•
_wctime64
•
_tctime64
•
mktime
•
_mktime64
•
_utime
•
_wutime
•
_tutime
•
_utime64
•
_wutime64
•
_tutime64
•
COleDateTime::operator=
•
CTime::GetLocalTm
•
CTime::Format
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 (http://support.microsoft.com/kb/824684/)
Description of the standard terminology that is used to describe Microsoft software updates
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