The following example sets the system time using the SetSystemTime function.
// SetNewTime - sets system time
// Return value - TRUE if successful, FALSE otherwise
// hour - new hour (0-23)
// minutes - new minutes (0-59)
BOOL SetNewTime(WORD hour, WORD minutes)
{
SYSTEMTIME st;
char *pc;
GetSystemTime(&st); // gets current time
st.wHour = hour; // adjusts hours
st.wMinute = minutes; // and minutes
if (!SetSystemTime(&st)) // sets system time
return FALSE;
return TRUE;
}