diff --git a/src/hiv_tx_network.js b/src/hiv_tx_network.js
index 3105502..e59774f 100755
--- a/src/hiv_tx_network.js
+++ b/src/hiv_tx_network.js
@@ -1230,6 +1230,11 @@ class HIVTxNetwork {
             (nr) => this.entity_id_from_string(nr.name)
           );
 
+          const entity_to_g_records = _.groupBy(
+            _.filter(g.node_objects, (nr) => !exclude_nodes.has(nr.id)),
+            (nr) => this.entity_id_from_string(nr.id)
+          );
+
           return _.map(
             _.filter(entities, (gn) => {
               return (
@@ -1248,8 +1253,10 @@ class HIVTxNetwork {
                 person_ident_dt: timeDateUtil.hivtrace_date_or_na_if_missing(
                   entity_to_pg_records[eid][0].added
                 ),
-                sample_dt: timeDateUtil.hivtrace_date_or_na_if_missing(
-                  this.attribute_node_value_by_id(gn, "sample_dt")
+                sample_dt: d3.min(entity_to_g_records[eid], (g) =>
+                  timeDateUtil.hivtrace_date_or_na_if_missing(
+                    this.attribute_node_value_by_id(g, "sample_dt")
+                  )
                 ),
                 new_linked_case: this.priority_groups_is_new_node(
                   entity_to_pg_records[eid][0]
diff --git a/src/timeDateUtil.js b/src/timeDateUtil.js
index b4a961d..fc03860 100644
--- a/src/timeDateUtil.js
+++ b/src/timeDateUtil.js
@@ -66,7 +66,11 @@ function getAncientDate() {
 function hivtrace_date_or_na_if_missing(date, formatter) {
   if (date) {
     formatter = formatter || DateViewFormatExport;
-    return formatter(date);
+    try {
+      return formatter(date);
+    } catch {
+      console.log(date);
+    }
   }
   return "N/A";
 }