/*$************************************************************************************************
 **
 ** $Id: TemporalDatum.java 831 2006-05-01 00:27:23Z Desruisseaux $
 **
 ** $URL: http://svn.code.sf.net/p/geoapi/code/branches/2.0.x/geoapi/src/main/java/org/opengis/referencing/datum/TemporalDatum.java $
 **
 ** Copyright (C) 2003-2005 Open GIS Consortium, Inc.
 ** All Rights Reserved. http://www.opengis.org/legal/
 **
 *************************************************************************************************/
package org.opengis.referencing.datum;

// J2SE direct dependencies
import java.util.Date;

// OpenGIS direct dependencies
import org.opengis.util.InternationalString;

// Annotations
import org.opengis.annotation.UML;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;


/**
 * A temporal datum defines the origin of a temporal coordinate reference system.
 *
 * @version Abstract specification 2.0
 * @author ISO/DIS 19111
 * @author Martin Desruisseaux (IRD)
 * @since GeoAPI 1.0
 */
@UML(identifier="CD_TemporalDatum", specification=ISO_19111)
public interface TemporalDatum extends Datum {
    /**
     * The date and time origin of this temporal datum.
     *
     * @return The date and time origin of this temporal datum.
     */
    @UML(identifier="origin", obligation=MANDATORY, specification=ISO_19111)
    Date getOrigin();

    /**
     * This attribute is defined in the {@link Datum} parent interface,
     * but is not used by a temporal datum.
     *
     * @return Always {@code null}.
     */
    @UML(identifier="anchorPoint", obligation=FORBIDDEN, specification=ISO_19111)
    InternationalString getAnchorPoint();

    /**
     * This attribute is defined in the {@link Datum} parent interface,
     * but is not used by a temporal datum.
     *
     * @return Always {@code null}.
     */
    @UML(identifier="realizationEpoch", obligation=FORBIDDEN, specification=ISO_19111)
    Date getRealizationEpoch();
}