public static int getDayNum() {
        int daynum = 0;
        GregorianCalendar gd = new GregorianCalendar();
        Date dt = gd.getTime();
        GregorianCalendar gd1 = new GregorianCalendar(1900, 1, 1);
        Date dt1 = gd1.getTime();
        daynum = (int) ((dt.getTime() - dt1.getTime()) / (24 * 60 * 60 * 1000));
        return daynum;
    }
public static int getDayNum() {
        int daynum = 0;
        GregorianCalendar gd = new GregorianCalendar();
        Date dt = gd.getTime();
        GregorianCalendar gd1 = new GregorianCalendar(1900, 1, 1);
        Date dt1 = gd1.getTime();
        daynum = (int) ((dt.getTime() - dt1.getTime()) / (24 * 60 * 60 * 1000));
        return daynum;
    }
public static int getDayNum ( ) { int daynum = 0 ; GregorianCalendar gd = new GregorianCalendar ( ) ; Date dt = gd . getTime ( ) ; GregorianCalendar gd1 = new GregorianCalendar ( 1900 , 1 , 1 ) ; Date dt1 = gd1 . getTime ( ) ; daynum = ( int ) ( ( dt . getTime ( ) - dt1 . getTime ( ) ) / ( 24 * 60 * 60 * 1000 ) ) ; return daynum ; }
取得当前时间距离1900/1/1的天数

@return 天数
取得当前时间距离1900 / 1 / 1的天数