Time Functions Calculate for Daylight Savings Time

Last reviewed: July 17, 1997
Article ID: Q39908

5.10 6.00 6.00a 6.00ax 7.00 | 5.10 6.00 6.00a | 1.00 1.50

MS-DOS                      | OS/2            | WINDOWS

kbprg

The information in this article applies to:

The C Run-time (CRT), included with:

    - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, and 6.0ax
    - Microsoft C for OS/2, versions 5.1, 6.0, and 6.0a
    - Microsoft C/C++ for MS-DOS, version 7.0
    - Microsoft Visual C++ for Windows, versions 1.0 and 1.5

The Microsoft time functions calculate for daylight saving time. In particular, mktime() will set the hour ahead or back one hour according to the rules of daylight saving time. The only way to change the dates that the time functions use in calculating daylight saving time is to get the run-time library source code available for the time functions and modify the routine _isindst() in the file TZSET.C.

Additional reference words: kbinf 1.00 1.50 6.00 6.00a 6.00ax 7.00
KBCategory: kbprg
KBSubcategory: CRTIss
Keywords : kb16bitonly

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Last reviewed: July 17, 1997
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