001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
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
043 package org.jfree.data.time;
044
045 import 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 */
051 public 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 }