Here you can find the source of isChristmas()
public static boolean isChristmas()
//package com.java2s; /*//from w w w .ja va 2 s .com * Copyright 2014 Lukas Tenbrink * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.Calendar; import static java.util.Calendar.*; public class Main { public static boolean isChristmas() { Calendar cal = getInstance(); int day = cal.get(DAY_OF_MONTH); return cal.get(MONTH) == DECEMBER && day == 23 || day == 24; } }