src/org/nutz/lang/Times.java
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