計算某一年的二月是多少天

package com.ugrow.lesson_Date;

import java.util.Calendar;

import java.util.Scanner;

public class Demo04 {

public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	System.out.println("請輸入年份：");
	int year = sc.nextInt();
	System.out.println(Rt(year));

}

public static long Rt(int year) {
	Calendar c = Calendar.getInstance();
	c.set(year, 2, 1);
	c.add(Calendar.DATE, -1);
	int day = c.get(Calendar.DATE);
	return day;
}
           

}