Subtracting 2 times to find hours and minutes?

Question

// Get Start Time
SYSTEMTIME stStart;
m_dtpCtrl[0].GetSystemTime(&stStart);

// Get End Time
SYSTEMTIME stEnd;
m_dtpCtrl[1].GetSystemTime(&stEnd);

// Get Start Day
SYSTEMTIME stStartDay;
m_dtpCtrl[2].GetSystemTime(&stStartDay);

//Get End Day
SYSTEMTIME stEndDay;
m_dtpCtrl[3].GetSystemTime(&stEndDay);

// Set Times up for Calculation
CTimeSpan tsStart(stStartDay.wDay, stStart.wHour, stStart.wMinute, stStart.wSecond);
CTimeSpan tsEnd(stEndDay.wDay, stEnd.wHour, stEnd.wMinute, stStart.wSecond);

// Perform Calulation of total time worked
CTimeSpan temp = tsEnd - tsStart;

pretty much just wanting to subtract 2 SYSTEMTIME struct from each other to get the time difference between them in order to calculate how long i've worked for a certain day!  from the above code after the calculations are performed i can call temp.GetTotalHours() and it will return the correct ammount of hours i worked for a particular day.  For some reason when i call temp.GetTotalMinutes() or even temp.GetMinutes() it always returns 0!!!! which is wrong when i alter the minute value of the SYSTEMTIME structs.  Does anyone have any idea what i'm doing wrong in the above calculation? like i said im just wanting to subtract 2 times in order to get the hours and minutes i worked for a particular day

**UPDATE**

the above calculation does work...it's something in my print statement.  For some reason the 2nd variable in the format statement always returns 0??? any ideas?

strTime.Format(_T("%d %d"), temp.GetTotalMinutes(), temp.GetTotalHours());

Answer 1

On 15/04/2012 16:50, lochnesse wrote:

the above calculation does work...it's something in my print statement.  For some reason the 2nd variable in the format statement always returns 0??? any ideas?



strTime.Format(_T("%d %d"), temp.GetTotalMinutes(), temp.GetTotalHours());

GetTotalMinutes and GetTotalHours return LONGLONG, so according to this table:

http://msdn.microsoft.com/en-us/library/tcxf1dw6(v=vs.100).aspx

you should use %lld as format specifier.

Giovanni