随便给你一个日期例如2009 8 20问这一天是否是星期六

[wang1986614]

随便给你一个日期例如2009 8 20问这一天是否是星期六

[fztjava]

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.io.*;

class test{



public final static String dayNames[] = {

"星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};



public static Date getdate(String date) throws Exception {

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

return sdf.parse(date);

}



public static void main(String[] args) throws Exception {

char k;

do{

System.out.print("请输入日期");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String d = br.readLine();

Calendar calendar = Calendar.getInstance();

calendar.setTime(getdate(d));

int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);

System.out.println(dayNames[dayOfWeek - 1]);



System.out.println("是否继续判断y代表是n代表退出");

BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));

k=(char)br1.read();

}while(k=='y');

System.out.println("已退出判断");

//可以将现在的时间输出

SimpleDateFormat currentDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss ");

System.out.println("完成编译时间为："+currentDateTime.format(new Date()));

}

}

[lovehuaihaibo]

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println();
		if(weekDay(2009,9,20) == 6){
			System.out.println("true");
		}else{
			System.out.println("false");
		}
	}
	
	public static int weekDay(int year,int month,int day){
		Calendar c = Calendar.getInstance();
		c.set(year, month-1, day);
		int week = c.get(Calendar.DAY_OF_WEEK);
		if(week == 1){
			return week+6;
		}
		return week-1;
	}

[flylovejings]

[Quote=引用 2 楼 lovehuaihaibo 的回复:]
Java codepublicstaticvoid main(String[] args) {// TODO Auto-generated method stub System.out.println();if(weekDay(2009,9,20)==6){
System.out.println("true");
}else{
¡­
[/Quote


mark

[o北斗o]

路过学习了~~~

[BeenZ]

<script language="javascript" type="text/javascript">

  function   fngetday(year,month,date)   
  {   
    var   keystr = "622503514624";
    var   deltmonth   =   parseInt(keystr.substr(month-1,1));   
    var   deltyear   =   (year-2000)+Math.ceil((year-2000)/4);   
    deltyear   +=   (year-Math.floor(year/4)*4==0   &&   month   >2   ?   1:0);   
    var   deltdate   =   date-1;   
    return   (deltmonth+deltyear+deltdate)   -   Math.floor((deltmonth+deltyear+deltdate)/7)*7;   
  } 
  document.write(fngetday(2008,2,19));
</script>

[BeenZ]

判断星期6的话就是

<script language="javascript" type="text/javascript">

  function   fngetday(year,month,date)   
  {   
    var   keystr = "622503514624";
    var   deltmonth   =   parseInt(keystr.substr(month-1,1));   
    var   deltyear   =   (year-2000)+Math.ceil((year-2000)/4);   
    deltyear   +=   (year-Math.floor(year/4)*4==0   &&   month   >2   ?   1:0);   
    var   deltdate   =   date-1;   
    return   (deltmonth+deltyear+deltdate)   -   Math.floor((deltmonth+deltyear+deltdate)/7)*7;   
  } 
  if(fngetday(2009,9,15)==6) alert("是星期6");
</script>

[wang1986614]

谢谢各位了，找到答案了！
W= (d+2*m+3*(m+1)/5+y+y/4-y/100+y/400) mod 7

在公式中d表示日期中的日数，m表示月份数，y表示年数。

注意：在公式中有个与其他公式不同的地方：

把一月和二月看成是上一年的十三月和十四月，例：如果是2004-1-10则换算成：2003-13-10来代入公式计算。
　// java code
　　//y－年，m－月，d－日期
　　string CaculateWeekDay(int y,int m, int d)
　　{
　　if(m==1||m==2) {
　　m+=12;
　　y--;
　　}
　　int week=(d+2*m+3*(m+1)/5+y+y/4-y/100+y/400)%7;
　　string weekstr="";
　　switch(week)
　　{
　　case 0: weekstr="星期一"; break;
　　case 1: weekstr="星期二"; break;
　　case 2: weekstr="星期三"; break;
　　case 3: weekstr="星期四"; break;
　　case 4: weekstr="星期五"; break;
　　case 5: weekstr="星期六"; break;
　　case 6: weekstr="星期日"; break;
　　}
　　return weekstr;
　　}