/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2011, Open Source Geospatial Foundation (OSGeo)
 *    (C) 2003-2005, Open Geospatial Consortium Inc.
 *    
 *    All Rights Reserved. http://www.opengis.org/legal/
 */
package org.opengis.referencing.datum;

import java.util.Date;
import org.opengis.util.InternationalString;
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.
 *
 *
 * @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/referencing/datum/TemporalDatum.java $
 * @version <A HREF="http://portal.opengeospatial.org/files/?artifact_id=6716">Abstract specification 2.0</A>
 * @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();
}