--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/states/sq/SQPeriodSelect.java	Wed Mar 25 19:18:43 2015 +0100
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/states/sq/SQPeriodSelect.java	Wed Mar 25 19:20:13 2015 +0100
@@ -8,14 +8,77 @@
 
 package org.dive4elements.river.artifacts.states.sq;
 
+import java.util.Date;
+import java.util.List;
+import java.util.Collections;
+
+import org.apache.log4j.Logger;
+
+import org.w3c.dom.Element;
+
 import org.dive4elements.river.artifacts.states.PeriodsSelect;
+import org.dive4elements.river.artifacts.access.RangeAccess;
+import org.dive4elements.river.artifacts.D4EArtifact;
+import org.dive4elements.river.artifacts.model.SQOverview;
+import org.dive4elements.river.artifacts.model.SQOverviewFactory;
+import org.dive4elements.river.artifacts.model.SQOverview.KmFilter;
+
+import org.dive4elements.river.utils.KMIndex;
+
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+
+import org.dive4elements.artifactdatabase.data.StateData;
 
 public class SQPeriodSelect extends PeriodsSelect {
 
+    private static Logger log = Logger.getLogger(SQPeriodSelect.class);
+
     public static final String UI_PROVIDER = "sq.period.select";
 
     private static final long serialVersionUID = 1L;
 
+    /** Get either the start date of the data or the end. */
+    protected long getDataMinMaxDate(Artifact artifact, boolean minDate) {
+        D4EArtifact arti = (D4EArtifact) artifact;
+        RangeAccess access = new RangeAccess(arti);
+        double km = access.getLocations()[0];
+
+        /* Bit of an overkill here but it will be cached and accessed
+         * in the next state anyway. */
+        SQOverview overview = SQOverviewFactory.getOverview(access.getRiverName());
+
+        KMIndex<List<Date>> entries = overview.filter(new KmFilter(km));
+        if (entries.size() == 0) {
+            return 0;
+        }
+        List<Date> dates = entries.get(0).getValue();
+        if (dates.isEmpty()) {
+            return 0;
+        }
+        Collections.sort(dates);
+
+        return minDate ? dates.get(0).getTime() : dates.get(dates.size() - 1).getTime();
+    }
+
+    @Override
+    protected Element[] createItems(
+        XMLUtils.ElementCreator cr,
+        Artifact    artifact,
+        String      name,
+        CallContext context)
+    {
+        if (!name.equals("start") && !name.equals("end")) {
+            return null;
+        }
+        Element def = createItem(
+            cr,
+            new String[] {"default", Long.toString(
+                getDataMinMaxDate(artifact, name.equals("start")))});
+
+        return new Element[] { def };
+    }
 
     @Override
     public String getUIProvider() {