diff --git a/base.php b/base.php
index 01ee13c4..85ac946b 100644
--- a/base.php
+++ b/base.php
@@ -9,7 +9,7 @@
 // | Author: liu21st <liu21st@gmail.com>
 // +----------------------------------------------------------------------
 
-define('THINK_VERSION', '5.0.4');
+define('THINK_VERSION', '5.0.5beta');
 define('THINK_START_TIME', microtime(true));
 define('THINK_START_MEM', memory_get_usage());
 define('EXT', '.php');
diff --git a/library/think/Model.php b/library/think/Model.php
index a1523914..4290cf68 100644
--- a/library/think/Model.php
+++ b/library/think/Model.php
@@ -96,7 +96,7 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
     // 更新时间字段
     protected $updateTime = 'update_time';
     // 时间字段取出后的默认时间格式
-    protected $dateFormat = 'Y-m-d H:i:s';
+    protected $dateFormat;
     // 字段类型或者格式转换
     protected $type = [];
     // 是否为更新数据
@@ -154,6 +154,11 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
             $this->autoWriteTimestamp = $this->db(false)->getConfig('auto_timestamp');
         }
 
+        if (is_null($this->dateFormat)) {
+            // 设置时间戳格式
+            $this->dateFormat = $this->db(false)->getConfig('datetime_format');
+        }
+
         // 执行初始化操作
         $this->initialize();
     }
@@ -329,12 +334,21 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
                 case 'integer':
                 default:
                     $value = $_SERVER['REQUEST_TIME'];
+                    if (strpos($type, '\\')) {
+                        // 传入类名
+                        $value = new $type($value);
+                    }
                     break;
             }
         } elseif (is_string($this->autoWriteTimestamp) && in_array(strtolower($this->autoWriteTimestamp), ['datetime', 'date', 'timestamp'])) {
             $value = date($this->dateFormat, $_SERVER['REQUEST_TIME']);
         } else {
             $value = $_SERVER['REQUEST_TIME'];
+            if (is_string($this->autoWriteTimestamp) && strpos($this->autoWriteTimestamp, '\\')) {
+                // 传入类名
+                $class = $this->autoWriteTimestamp;
+                $value = new $class($value);
+            }
         }
         return $value;
     }
@@ -484,6 +498,10 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
             case 'serialize':
                 $value = unserialize($value);
                 break;
+            default:
+                if (strpos($type, '\\')) {
+                    $value = new $type($value);
+                }
         }
         return $value;
     }
diff --git a/library/think/db/Connection.php b/library/think/db/Connection.php
index f7d33161..f3138421 100644
--- a/library/think/db/Connection.php
+++ b/library/think/db/Connection.php
@@ -65,47 +65,49 @@ abstract class Connection
     // 数据库连接参数配置
     protected $config = [
         // 数据库类型
-        'type'           => '',
+        'type'            => '',
         // 服务器地址
-        'hostname'       => '',
+        'hostname'        => '',
         // 数据库名
-        'database'       => '',
+        'database'        => '',
         // 用户名
-        'username'       => '',
+        'username'        => '',
         // 密码
-        'password'       => '',
+        'password'        => '',
         // 端口
-        'hostport'       => '',
+        'hostport'        => '',
         // 连接dsn
-        'dsn'            => '',
+        'dsn'             => '',
         // 数据库连接参数
-        'params'         => [],
+        'params'          => [],
         // 数据库编码默认采用utf8
-        'charset'        => 'utf8',
+        'charset'         => 'utf8',
         // 数据库表前缀
-        'prefix'         => '',
+        'prefix'          => '',
         // 数据库调试模式
-        'debug'          => false,
+        'debug'           => false,
         // 数据库部署方式:0 集中式(单一服务器),1 分布式(主从服务器)
-        'deploy'         => 0,
+        'deploy'          => 0,
         // 数据库读写是否分离 主从式有效
-        'rw_separate'    => false,
+        'rw_separate'     => false,
         // 读写分离后 主服务器数量
-        'master_num'     => 1,
+        'master_num'      => 1,
         // 指定从服务器序号
-        'slave_no'       => '',
+        'slave_no'        => '',
         // 是否严格检查字段是否存在
-        'fields_strict'  => true,
+        'fields_strict'   => true,
         // 数据集返回类型
-        'resultset_type' => 'array',
+        'resultset_type'  => 'array',
         // 自动写入时间戳字段
-        'auto_timestamp' => false,
+        'auto_timestamp'  => false,
+        // 时间戳格式
+        'datetime_format' => 'Y-m-d H:i:s',
         // 是否需要进行SQL性能分析
-        'sql_explain'    => false,
+        'sql_explain'     => false,
         // Builder类
-        'builder'        => '',
+        'builder'         => '',
         // Query类
-        'query'          => '\\think\\db\\Query',
+        'query'           => '\\think\\db\\Query',
     ];
 
     // PDO连接参数