Application: gvSIG desktop

/* gvSIG. Geographic Information System of the Valencian Government

 *

 * Copyright (C) 2007-2008 Infrastructures and Transports Department

 * of the Valencian Government (CIT)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 */

package org.gvsig.timesupport;

/**

 * <p>

 * Chronology provides access to the individual date time fields for a

 * chronological calendar system.

 * </p> 

 *  <p>

 * Various chronologies are supported by subclasses including ISO

 * and GregorianJulian. To construct a Chronology you should use the

 * factory methods on the {@link TimeSupportManager}.

 * <p>

 * The provided chronology implementations are:

 * <ul>

 * <li>ISO - Based on the ISO8601 standard and suitable for use after about 1600

 * <li>GJ - Historically accurate calendar with Julian followed by Gregorian

 * <li>Gregorian - The Gregorian calendar system used for all time (proleptic)

 * <li>Julian - The Julian calendar system used for all time (proleptic)

 * <li>Buddhist - The Buddhist calendar system which is an offset in years from GJ

 * <li>Coptic - The Coptic calendar system which defines 30 day months

 * <li>Ethiopic - The Ethiopic calendar system which defines 30 day months

 * </ul>

 * </p>

 * <p>

 * Instances of this class are singletons and they can be compared using the

 * {@link Chronology}{@link #getType()} method and the <code>==</code>

 * operator.

 * </p>

 * <p>

 * A huge part of the documentation of this class has been retrieved

 * from the joda-time library.

 * </p>

 * 

 * @see http://joda-time.sourceforge.net

 * @see https://gvsig.org/web/projects/gvsig-desktop/docs/devel/org-gvsig-sensors/1-0.0/analysis-and-design/detailed-view/time-support/libraries/org-gvsig-timesupport-lib

 * 

 * @author gvSIG Team

 * @version $Id$

 *

 */

public interface Chronology {

    public static final int BUDDHIST = 1;

    public static final int COPTIC = 2;

    public static final int GJ = 3;

    public static final int GREGORIAN = 4;

    public static final int ISO = 5;

    public static final int JULIAN = 6;

    /**

     * Gets the code of the type, that is one of the constants defined

     * in the {@link Chronology} class.

     * @return

     *            the type code

     */

    public int getType();    

    /**

     * Returns an instance of this Chronology that operates in the UTC time

     * zone. Chronologies that do not operate in a time zone or are already

     * UTC must return themself.

     * @return 

     *          a version of this chronology that ignores time zones

     */

    public Chronology withUTC();

}