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Adding a day not working


I have this in the declarations:
CTimeSpan                  tTimeSpanOneDay(1, 0 , 0 , 0) ;

Later on I have this:
CTime      dNewNextPayDate(nNewYear, nNewMonth, nNewDay , 0, 0, 0) ;
tRetNextPayDate = dNewNextPayDate ;

tRetNextPayDate  is equal to 10/31/2004 at this point.

When I do this:
tRetNextPayDate = tRetNextPayDate +  tTimeSpanOneDay;

tRetNextPayDate still has 10/31/2004 in it.

If I create the date like this:
CTime      dNewNextPayDate(nNewYear, nNewMonth, nNewDay , 12, 0, 0) ;  <-- added the 12

Then the date addition yeilds the correct new date, 11/1/2004.

What's going on here?
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nonubik
I tried this code:

CTimeSpan               tTimeSpanOneDay(1, 0 , 0 , 0) ;

      CTime     dNewNextPayDate(2004, 10, 31 , 0, 0, 0) ;
      CTime      tRetNextPayDate = dNewNextPayDate ;

      //tRetNextPayDate  is equal to 10/31/2004 at this point.
      int iD = tRetNextPayDate.GetDay();
      int iy = tRetNextPayDate.GetYear();
      int im = tRetNextPayDate.GetMonth();
      int ih = tRetNextPayDate.GetHour();

      // here iD = 31, iy=2004, im=10, ih=0
      tRetNextPayDate = tRetNextPayDate +  tTimeSpanOneDay;

      iD = tRetNextPayDate.GetDay();
      iy = tRetNextPayDate.GetYear();
      im = tRetNextPayDate.GetMonth();
      ih = tRetNextPayDate.GetHour();
      // here iD = 1, iy=2004, im=11, ih=0

So it works on my side.
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drichards
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nonubik
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drichards
OK, here's what I came up with:

1) Use the MS workaround from the Knowledge Base article - you'll have to be careful about side effects on this one.

2) Use ColeDateTime/COleDateTimeSpan instead (doesn't use daylight time)

3) If you don't care about the time portion (you're just doing full day calculations) set the initial CTime time to 12:00:00.  Your time will fluctuate +- 1 hour on the daylight changeovers, but the date will be correct.  If you care about partial days, this will not work.