diff --git a/declarationtvaindex.php b/declarationtvaindex.php
index e230b8c..f1d997a 100644
--- a/declarationtvaindex.php
+++ b/declarationtvaindex.php
@@ -75,7 +75,7 @@ if ($action == 'create_declaration' && $period_id > 0) {
 $declarations = array();
 
 // Get all declarations
-$sql = "SELECT d.*, p.period_name, p.start_date, p.end_date 
+$sql = "SELECT d.*, p.period_name, p.start_date as period_start_date, p.end_date as period_end_date 
         FROM " . MAIN_DB_PREFIX . "declarationtva_declarations d
         LEFT JOIN " . MAIN_DB_PREFIX . "declarationtva_periods p ON d.period_id = p.rowid
         WHERE d.entity = " . $conf->entity . " 
@@ -84,6 +84,11 @@ $sql = "SELECT d.*, p.period_name, p.start_date, p.end_date
 $result = $db->query($sql);
 if ($result) {
     while ($obj = $db->fetch_object($result)) {
+        // Use declaration's own dates if period is not available
+        $start_date = $obj->start_date ? $obj->start_date : $obj->period_start_date;
+        $end_date = $obj->end_date ? $obj->end_date : $obj->period_end_date;
+        $period_name = $obj->period_name ? $obj->period_name : 'Custom Period';
+        
         $declarations[] = array(
             'rowid' => $obj->rowid,
             'declaration_number' => $obj->declaration_number,
@@ -93,9 +98,9 @@ if ($result) {
             'net_vat_due' => $obj->net_vat_due,
             'vat_credit' => $obj->vat_credit,
             'created_date' => $obj->created_date,
-            'period_name' => $obj->period_name,
-            'start_date' => $obj->start_date,
-            'end_date' => $obj->end_date
+            'period_name' => $period_name,
+            'start_date' => $start_date,
+            'end_date' => $end_date
         );
     }
 }