1 //根据日期计算星期几                 
 2                                                 
 3  int SDGSELFLocalTime::CalWhatDay(ST_LOCALDATE& l_stDate)
 4 {
 5  int year = l_stDate.m_nYear;
 6  int month = l_stDate.m_nMonth;
 7  int day = l_stDate.m_nDay;
 8  if (month < 3)
 9  {
10   year -= 1;
11   month += 12;
12  }
13  int c = int(year / 100) , y = year - 100 * c;
14  int w = int(c / 4) - 2*c +y +int(y/4) +(26 * (month + 1)/10) + day - 1;
15  w = (w % 7 + 7) % 7;
16  return w;
17 }