001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ---------------
028 * TimePeriod.java
029 * ---------------
030 * (C) Copyright 2003-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 10-Jan-2003 : Version 1 (DG);
038 * 13-Mar-2003 : Moved to com.jrefinery.data.time package (DG);
039 * 27-Jan-2005 : Implemented Comparable (DG);
040 *
041 */
042
043package org.jfree.data.time;
044
045import java.util.Date;
046
047/**
048 * A period of time measured to millisecond precision using two instances of
049 * <code>java.util.Date</code>.
050 */
051public interface TimePeriod extends Comparable {
052
053    /**
054     * Returns the start date/time.  This will always be on or before the
055     * end date.
056     *
057     * @return The start date/time (never <code>null</code>).
058     */
059    public Date getStart();
060
061    /**
062     * Returns the end date/time.  This will always be on or after the
063     * start date.
064     *
065     * @return The end date/time (never <code>null</code>).
066     */
067    public Date getEnd();
068
069}