diff --git a/core/class/declarationtva.class.php b/core/class/declarationtva.class.php
index 758d22f..b2ac3a9 100644
--- a/core/class/declarationtva.class.php
+++ b/core/class/declarationtva.class.php
@@ -78,6 +78,45 @@ class DeclarationTVA
         return $declaration_id;
     }
 
+    /**
+     * Create a new declaration with specific dates
+     *
+     * @param string $start_date Start date (YYYY-MM-DD)
+     * @param string $end_date End date (YYYY-MM-DD)
+     * @param string $declaration_name Declaration name
+     * @return int Declaration ID or -1 if error
+     */
+    public function createDeclarationWithDates($start_date, $end_date, $declaration_name = '')
+    {
+        global $user;
+
+        $this->db->begin();
+
+        // Generate declaration number
+        $declaration_number = $this->generateDeclarationNumberFromDates($start_date, $end_date);
+
+        // Create declaration record
+        $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_declarations 
+                (entity, period_id, declaration_number, declaration_name, start_date, end_date, status, created_date) 
+                VALUES (" . $this->entity . ", 0, '" . $declaration_number . "', '" . $this->db->escape($declaration_name) . "', '" . $start_date . "', '" . $end_date . "', 'draft', NOW())";
+
+        $result = $this->db->query($sql);
+        if (!$result) {
+            $this->error = "Error creating declaration: " . $this->db->lasterror();
+            $this->db->rollback();
+            return -1;
+        }
+
+        $declaration_id = $this->db->last_insert_id(MAIN_DB_PREFIX . "declarationtva_declarations");
+
+        // Calculate CA-3 amounts
+        $period = array('start_date' => $start_date, 'end_date' => $end_date);
+        $this->calculateCA3Amounts($declaration_id, $period);
+
+        $this->db->commit();
+        return $declaration_id;
+    }
+
     /**
      * Calculate CA-3 amounts for a declaration
      *
@@ -257,6 +296,21 @@ class DeclarationTVA
         return 'CA3-' . $year . '-Q' . $quarter . '-' . date('YmdHis');
     }
 
+    /**
+     * Generate declaration number from dates
+     *
+     * @param string $start_date Start date
+     * @param string $end_date End date
+     * @return string Declaration number
+     */
+    public function generateDeclarationNumberFromDates($start_date, $end_date)
+    {
+        $year = date('Y', strtotime($start_date));
+        $quarter = ceil(date('n', strtotime($start_date)) / 3);
+        
+        return 'CA3-' . $year . '-Q' . $quarter . '-' . date('YmdHis');
+    }
+
     /**
      * Get declaration information
      *
diff --git a/declarationtva_create.php b/declarationtva_create.php
index aae441c..164c495 100644
--- a/declarationtva_create.php
+++ b/declarationtva_create.php
@@ -38,7 +38,6 @@ $period = new DeclarationTVA_Period($db, $conf->entity);
 
 // Handle form submission
 $action = GETPOST('action', 'alpha');
-$period_id = GETPOST('period_id', 'int');
 $declaration_name = GETPOST('declaration_name', 'alpha');
 $start_date = GETPOST('start_date', 'alpha');
 $end_date = GETPOST('end_date', 'alpha');
@@ -46,9 +45,9 @@ $end_date = GETPOST('end_date', 'alpha');
 $error = '';
 $success = '';
 
-if ($action == 'create' && $period_id > 0) {
-    // Create the declaration
-    $declaration_id = $declarationtva->createDeclaration($period_id, $declaration_name);
+if ($action == 'create' && !empty($start_date) && !empty($end_date)) {
+    // Create the declaration with dates
+    $declaration_id = $declarationtva->createDeclarationWithDates($start_date, $end_date, $declaration_name);
     
     if ($declaration_id > 0) {
         $success = $langs->trans("DeclarationCreated");
@@ -60,9 +59,6 @@ if ($action == 'create' && $period_id > 0) {
     }
 }
 
-// Get available periods
-$periods = $period->getAllPeriods();
-
 // Page title
 $title = $langs->trans("CreateDeclaration");
 llxHeader('', $title);
@@ -87,21 +83,14 @@ print '<input type="hidden" name="action" value="create">';
 
 print '<table class="noborder centpercent">';
 
-// Period selection
+// Date range (now mandatory and at the top)
 print '<tr>';
 print '<td class="fieldrequired">' . $langs->trans("SelectPeriod") . '</td>';
 print '<td>';
-print '<select name="period_id" class="flat" required>';
-print '<option value="">' . $langs->trans("ChoosePeriod") . '</option>';
-
-foreach ($periods as $p) {
-    $selected = ($period_id == $p['rowid']) ? ' selected' : '';
-    print '<option value="' . $p['rowid'] . '"' . $selected . '>';
-    print $p['period_name'] . ' (' . dol_print_date($p['start_date'], 'day') . ' - ' . dol_print_date($p['end_date'], 'day') . ')';
-    print '</option>';
-}
-
-print '</select>';
+print '<input type="date" name="start_date" class="flat" value="' . dol_escape_htmltag($start_date) . '" required>';
+print ' - ';
+print '<input type="date" name="end_date" class="flat" value="' . dol_escape_htmltag($end_date) . '" required>';
+print '<br><small>' . $langs->trans("DateRangeHelp") . '</small>';
 print '</td>';
 print '</tr>';
 
@@ -114,17 +103,6 @@ print '<br><small>' . $langs->trans("DeclarationNameHelp") . '</small>';
 print '</td>';
 print '</tr>';
 
-// Date range (optional override)
-print '<tr>';
-print '<td>' . $langs->trans("DateRange") . '</td>';
-print '<td>';
-print '<input type="date" name="start_date" class="flat" value="' . dol_escape_htmltag($start_date) . '">';
-print ' - ';
-print '<input type="date" name="end_date" class="flat" value="' . dol_escape_htmltag($end_date) . '">';
-print '<br><small>' . $langs->trans("DateRangeHelp") . '</small>';
-print '</td>';
-print '</tr>';
-
 print '</table>';
 
 // Buttons