Registrations are now open. Join us today!
There is still a lot of work to do on the wiki yet! More information about editing can be found here.
Already have an account?

Microsoft KB Archive/102215

From BetaArchive Wiki

BUG: TYPES.H time_t Definition Is Incorrect


The information in this article applies to:

  • The C Run-Time (CRT), included with:
    • Microsoft Visual C++, versions 1.0, 1.5, 1.51


The Microsoft Visual C++ run-time library time functions, such as mktime(), use the time_t data type which is defined in TIME.H as a long. However, the SYS\TYPES.H file incorrectly defines the time_t data type as an unsigned long.


Perform one of the following two steps to work around this problem:

  • Modify the SYS\TYPES.H file to modify the time_t definition from unsigned long to long
  • Include TIME.H before SYS\TYPES.H to use the correct time_t definition


Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.


This information does not apply to Microsoft C/C++ version 7.0 because the TIME.H and SYS\TYPES.H file each define time_t as an unsigned long. Nor does it apply to Microsoft C versions 6.0x or Microsoft Visual C++ 32-bit Edition because the TIME.H and SYS\TYPES.H file each define time_t as a long.

For additional information about the differences between the time_t data type in C versions 6.0x and the time_t data type in C/C++ version 7.0, please query in the Microsoft Knowledge Base on the following words:

time function changes gmt

Additional query words: 6.00 7.00 1.00 1.50

Keywords : kb16bitonly
Issue type : kbbug
Technology : kbVCsearch kbAudDeveloper kbCRT

Last Reviewed: May 8, 2001
© 2001 Microsoft Corporation. All rights reserved. Terms of Use.