//通过日期获取Week
long GetWeekByDate(const long& lDateTime){
//当前年份
long lYear = (lDateTime/10000);
//当前月份
long lMonth = (lDateTime%10000)/100;
if(lMonth == 1 || lMonth == 2){
lMonth += 12;
--lYear;
}
return ((lDateTime%100) + 2 * lMonth + 3 * (lMonth + 1)/5 +
lYear + lYear/4 - lYear/100 + lYear/400 + 1)%7;
}