Here you can find the source of diff(Date earlier, Date later, TimeUnit timeUnit)
public static long diff(Date earlier, Date later, TimeUnit timeUnit)
//package com.java2s; /*-------------------------------------------------------------------------+ | | | Copyright 2005-2011 The ConQAT Project | | | | 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.Date; import java.util.concurrent.TimeUnit; public class Main { /**/*from w ww .j a va 2 s. c om*/ * Returns the difference between two dates in the given time unit. */ public static long diff(Date earlier, Date later, TimeUnit timeUnit) { long diffInMillies = later.getTime() - earlier.getTime(); return timeUnit.convert(diffInMillies, TimeUnit.MILLISECONDS); } }