diff --git a/application/config/migration.php b/application/config/migration.php
index 957d49d0..38343334 100755
--- a/application/config/migration.php
+++ b/application/config/migration.php
@@ -21,7 +21,7 @@ $config['migration_enabled'] = TRUE;
 | be upgraded / downgraded to.
 |
 */
-$config['migration_version'] = 20;
+$config['migration_version'] = 21;
 
 
 /*
diff --git a/application/migrations/021_modify_sync_period_columns.php b/application/migrations/021_modify_sync_period_columns.php
new file mode 100644
index 00000000..58754164
--- /dev/null
+++ b/application/migrations/021_modify_sync_period_columns.php
@@ -0,0 +1,106 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        http://easyappointments.org
+ * @since       v1.4.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Class Migration_Modify_sync_period_columns
+ *
+ * @property CI_DB_query_builder $db
+ * @property CI_DB_forge $dbforge
+ */
+class Migration_Modify_sync_period_columns extends CI_Migration {
+    /**
+     * Upgrade method.
+     */
+    public function up()
+    {
+        $fields = [
+            'sync_past_days' => [
+                'type' => 'INT',
+                'constraint' => '11',
+                'null' => TRUE,
+                'default' => '30'
+            ],
+            'sync_future_days' => [
+                'type' => 'INT',
+                'constraint' => '11',
+                'null' => TRUE,
+                'default' => '90'
+            ],
+        ];
+
+        $this->dbforge->modify_column('user_settings', $fields);
+
+        $this->db->update(
+            'user_settings',
+            [
+                'sync_past_days' => '30'
+            ],
+            [
+                'sync_past_days' => '5'
+            ]
+        );
+
+        $this->db->update(
+            'user_settings',
+            [
+                'sync_future_days' => '90'
+            ],
+            [
+                'sync_future_days' => '5'
+            ]
+        );
+    }
+
+    /**
+     * Downgrade method.
+     */
+    public function down()
+    {
+        $fields = [
+            'sync_past_days' => [
+                'type' => 'INT',
+                'constraint' => '11',
+                'null' => TRUE,
+                'default' => '5'
+            ],
+            'sync_future_days' => [
+                'type' => 'INT',
+                'constraint' => '11',
+                'null' => TRUE,
+                'default' => '5'
+            ],
+        ];
+
+        $this->dbforge->modify_column('user_settings', $fields);
+
+        $this->db->update(
+            'user_settings',
+            [
+                'sync_past_days' => '5'
+            ],
+            [
+                'sync_past_days' => '30'
+            ]
+        );
+
+        $this->db->update(
+            'user_settings',
+            [
+                'sync_future_days' => '5'
+            ],
+            [
+                'sync_future_days' => '90'
+            ]
+        );
+    }
+}