diff --git a/borax/calendars/festivals2.py b/borax/calendars/festivals2.py
index ce4fa17..e84de7f 100644
--- a/borax/calendars/festivals2.py
+++ b/borax/calendars/festivals2.py
@@ -65,17 +65,25 @@ class FestivalSchema(enum.IntEnum):
 
 class WrappedDate:
     """A date object with solar and lunar calendars."""
-    __slots__ = ['solar', 'lunar', 'name', '_fl']
+    __slots__ = ['_solar', '_lunar', 'name', '_fl']
 
     def __init__(self, date_obj: MixedDate, name: str = ''):
-        self.solar = LCalendars.cast_date(date_obj, date)
-        self.lunar = LCalendars.cast_date(date_obj, LunarDate)
+        self._solar = LCalendars.cast_date(date_obj, date)
+        self._lunar = LCalendars.cast_date(date_obj, LunarDate)
         self.name = name
         if isinstance(date_obj, date):
             self._fl = 's'
         else:
             self._fl = 'l'
 
+    @property
+    def solar(self):
+        return self._solar
+
+    @property
+    def lunar(self):
+        return self._lunar
+
     def __iter__(self):
         yield self.solar
         yield self.lunar
@@ -122,13 +130,6 @@ def __hash__(self):
     def __eq__(self, other):
         return isinstance(self, type(other)) and self.__key() == other.__key()
 
-    def __getstate__(self):
-        return self.__key()
-
-    def __setstate__(self, state):
-        _year, _month, _day = state
-        self.solar = date(_year, _month, _day)
-
     def full_str(self):
         return f'{self.solar}({self.lunar.cn_str()})'
 
diff --git a/borax/capp/borax_calendar_app.py b/borax/capp/borax_calendar_app.py
index de4e024..bc5e2fb 100644
--- a/borax/capp/borax_calendar_app.py
+++ b/borax/capp/borax_calendar_app.py
@@ -18,8 +18,6 @@
 
 library = FestivalLibrary.load_builtin().sort_by_countdown()
 
-__VERSION__ = '1.1.0'
-
 PROJECT_URLS = {
     'home': 'https://github.com/kinegratii/borax'
 }
@@ -347,7 +345,7 @@ def start_festival_dlg(self):
             self._create_festival_dialog()
 
     def show_about_info(self):
-        showinfo('关于', f' 日历v{__VERSION__}\n\n Powered by Borax{borax_version}')
+        showinfo('关于', f' 日历v{borax_version}\n\n Powered by Borax{borax_version}')
 
 
 def start_calendar_app():
@@ -356,7 +354,7 @@ def start_calendar_app():
     x, y = int(root.winfo_screenwidth() / 2 - rw / 2), int(root.winfo_screenheight() / 2 - rh / 2)
     root.geometry(f"{rw}x{rh}+{x}+{y}")
     root.resizable(False, False)
-    root.title(f'日历 - v{__VERSION__}')
+    root.title(f'日历 - v{borax_version}')
     global style
     style = ttk.Style(root)
     # style.theme_use('alt')
diff --git a/docs/changelog.md b/docs/changelog.md
index e7a7276..23d1e92 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -13,6 +13,7 @@
   - 新增方法 `FestivalLibrary.load`
   - 新增 `borax.ui.widgets.MessageLabel` 类
   - `Festival` 类新增 `code` 属性
+  - `WrappedDate.solar` 和 `WrappedDate.lunar` 属性变更为只读属性，不可写入
 - 项目构建
   - 不再支持python3.7和python3.8
   - 本地开发环境更新至 python3.11.7
diff --git a/mkdocs.yaml b/mkdocs.yaml
index c17a294..b80922b 100644
--- a/mkdocs.yaml
+++ b/mkdocs.yaml
@@ -9,6 +9,10 @@ theme:
     - navigation.tabs
     - navigation.sections
     - navigation.footer
+validation:
+  links:
+    absolute_links: ignore
+    unrecognized_links: ignore
 extra:
   social:
     - icon: fontawesome/brands/github
diff --git a/tests/test_date_pickle.py b/tests/test_date_pickle.py
index 1e0c29c..bb60b80 100644
--- a/tests/test_date_pickle.py
+++ b/tests/test_date_pickle.py
@@ -2,13 +2,24 @@
 import pickle
 from io import BytesIO
 
+from datetime import date
+
 from borax.calendars.lunardate import LunarDate
 from borax.calendars.festivals2 import WrappedDate
 
 
+class WrappedDateBasicTestCase(unittest.TestCase):
+    def test_wrapped_date(self):
+        ld = LunarDate.today()
+        wd = WrappedDate(ld)
+        self.assertEqual(ld, wd.lunar)
+        with self.assertRaises(AttributeError):
+            wd.lunar = LunarDate(2024, 1, 1)
+
+
 class DatePickleTestCase(unittest.TestCase):
 
-    def test_wd(self):
+    def test_lunardate_pickle(self):
         ld1 = LunarDate.today()
         fp = BytesIO()
 
@@ -18,11 +29,13 @@ def test_wd(self):
         e_ld = pickle.load(fp)
         self.assertEqual(ld1, e_ld)
 
-        wd1 = WrappedDate(ld1)
-        fp2 = BytesIO()
-
-        pickle.dump(wd1, fp2)
-
-        fp2.seek(0)
-        wd2 = pickle.load(fp2)
-        self.assertEqual(wd2, wd1)
+    def test_wrapped_date_pickle(self):
+        wd_list = [WrappedDate(date.today()), WrappedDate(LunarDate.today())]
+        for wd in wd_list:
+            with self.subTest(wd=wd):
+                fp = BytesIO()
+                pickle.dump(wd, fp)
+                fp.seek(0)
+                new_wd = pickle.load(fp)
+                self.assertEqual(wd.solar, new_wd.solar)
+                self.assertEqual(wd.lunar, new_wd.lunar)