Here you can find the source of getLastDayOfMonth(final Date date)
public static Date getLastDayOfMonth(final Date date)
//package com.java2s; /**/* ww w. j a va 2 s. co m*/ * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 java.util.Date; public class Main { public static Date getLastDayOfMonth(final Date date) { Calendar src = Calendar.getInstance(); src.setTime(date); Calendar dst = getLastDayOfMonth(src); return dst.getTime(); } public static Calendar getLastDayOfMonth(final Calendar calendar) { int lastDay = calendar.getActualMaximum(Calendar.DATE); Calendar cln = Calendar.getInstance(); cln.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), lastDay, 0, 0, 0); return cln; } }