如何根据1900年1月1日到某一日的天数来获得某一日日期？

例如1900年1月1日 到 2010年11月18日 的总天数为 40498

已知 40498
如何计算出1900年1月1日后的40498天是2010年11月18日呢？

注：用java来实现

[quote]
Java代码

public static void main(String[] args) {

Calendar cal = Calendar.getInstance();

cal.set(1900, 0, 1);

// Calendar cal2 = Calendar.getInstance();

// cal2.set(2010, 10, 18);

//

// long calm = cal.getTimeInMillis();

// long cal2m = cal2.getTimeInMillis();

// long re = (cal2m - calm)/1000/60/60/24;

// System.out.println(re);

cal.add(Calendar.DAY_OF_MONTH, 40498);

    System.out.println(cal.get(Calendar.YEAR));  
    System.out.println(cal.get(Calendar.MONTH));  
    System.out.println(cal.get(Calendar.DAY_OF_MONTH));  

}  

LeeYee (中级程序员) 2012-03-16

[/quote]

更正下，cal.get(Calendar.MONTH)定义的月是从0开始的，也就是0代表一月。

[code="java"] public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
cal.set(1900, 0, 1);
cal.add(Calendar.DAY_OF_MONTH, 40498);

    System.out.print(cal.get(Calendar.YEAR) + "年");
    System.out.print(cal.get(Calendar.MONTH) + 1 + "月");
    System.out.println(cal.get(Calendar.DAY_OF_MONTH) + "日");

}[/code]

其实你可以直接查看Calendar API，API里有详细的说明

[code="java"]
Calendar car = Calendar.getInstance();
car.set(Calendar.YEAR, 1900);
car.set(Calendar.MONTH, 1);
car.set(Calendar.DAY_OF_YEAR, 1);
car.add(Calendar.DAY_OF_YEAR, 40498 );
System.out.println(car.getTime());
[/code]

[code="java"]
public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
cal.set(1900, 0, 1);
// Calendar cal2 = Calendar.getInstance();
// cal2.set(2010, 10, 18);
//
// long calm = cal.getTimeInMillis();
// long cal2m = cal2.getTimeInMillis();
// long re = (cal2m - calm)/1000/60/60/24;
// System.out.println(re);
cal.add(Calendar.DAY_OF_MONTH, 40498);

    System.out.println(cal.get(Calendar.YEAR));
    System.out.println(cal.get(Calendar.MONTH));
    System.out.println(cal.get(Calendar.DAY_OF_MONTH));

}

[/code]

[code="java"]
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import org.apache.commons.lang.time.DateUtils;

public class TestDate {

public static void main(String[] args){

    Calendar c = new GregorianCalendar(1900,0,1);
    Date d = c.getTime();
    System.out.println(d.toLocaleString());
    Date _d = DateUtils.addDays(d, 40498);
    System.out.println(_d.toLocaleString());
}

}[/code]