Here you can find the source of toDays(Date date)
public static Long toDays(Date date)
//package com.java2s; /*//from w w w . j a v a 2 s .com * Copyright: (c) 2004-2012 Mayo Foundation for Medical Education and * Research (MFMER). All rights reserved. MAYO, MAYO CLINIC, and the * triple-shield Mayo logo are trademarks and service marks of MFMER. * * Except as contained in the copyright notice above, or as used to identify * MFMER as the author of this software, the trade names, trademarks, service * marks, or product names of the copyright holder shall not be used in * advertising, promotion or otherwise in connection with this software without * prior written authorization of the copyright holder. * * 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.*; public class Main { public static Long toDays(Date date) { if (date == null) { return null; } else { return new Long(java.util.concurrent.TimeUnit.MILLISECONDS.toDays(date.getTime())); } } }