Here you can find the source of isLeapYear(int y)
public static final boolean isLeapYear(int y)
//package com.java2s; //License from project: Open Source License public class Main { public static final boolean isLeapYear(int y) { if (y % 4 == 0) { if (y % 100 == 0) { if (y % 400 == 0) { return true; } else { return false; }//from w ww. j a va 2s. c o m } else { return true; } } return false; } }