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Q130769: FIX: Negative Value Passed to mktime() Generates Wrong Date

Article: Q130769
Product(s): Microsoft C Compiler
Version(s): 2.0,2.1
Operating System(s): 
Keyword(s): kbList kbCompiler
Last Modified: 25-JUL-2001

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The information in this article applies to:

- Microsoft C/C++ Compiler (CL.EXE), included with:
   - *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, versions 2.0, 2.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

The wrong date is returned when a negative value is passed for the month to the
mktime() function.

For example, in the sample code in this article, -1 is passed for the month, so
the mktime() function should return December 15, 1994. However, it incorrectly
returns January 16, 1995.

RESOLUTION
==========

Verify that the value for the month is greater than or equal to zero, when
calling the mktime() function.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Microsoft Visual C++,
32-bit Edition, version 4.0.

MORE INFORMATION
================

Sample Code to Reproduce Problem
--------------------------------

     /* Compile options needed: none
     */ 

     #include <time.h>
     #include <stdio.h>

     void main() {
         time_t   CurrentTime, NewTime;
         struct tm TimeStruct;

         time ( &CurrentTime );
         TimeStruct = *localtime(&CurrentTime);
         TimeStruct.tm_mday = 15;
         TimeStruct.tm_mon  = -1;
         TimeStruct.tm_year = 95;

         NewTime = mktime (&TimeStruct);
         printf("%s", asctime( &TimeStruct));
     }

Additional query words: 9.00 9.10

======================================================================
Keywords          : kbList kbCompiler 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :2.0,2.1
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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