/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * TimePeriod.java
 * ---------------
 * (C) Copyright 2003-2005, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: TimePeriod.java,v 1.3.2.1 2005/10/25 21:35:24 mungady Exp $
 *
 * Changes
 * -------
 * 10-Jan-2003 : Version 1 (DG);
 * 13-Mar-2003 : Moved to com.jrefinery.data.time package (DG);
 * 27-Jan-2005 : Implemented Comparable (DG);
 *
 */

package org.jfree.data.time;

import java.util.Date;

/**
 * A period of time measured to millisecond precision using two instances of
 * <code>java.util.Date</code>.
 */
public interface TimePeriod extends Comparable {

    /**
     * Returns the start date/time.  This will always be on or before the 
     * end date.
     *
     * @return The start date/time (never <code>null</code>).
     */
    public Date getStart();

    /**
     * Returns the end date/time.  This will always be on or after the 
     * start date.
     *
     * @return The end date/time (never <code>null</code>).
     */
    public Date getEnd();

}
