diff --git a/.flake8 b/.flake8
index ea09b9d6..8a4bef99 100644
--- a/.flake8
+++ b/.flake8
@@ -16,6 +16,8 @@ ignore=
     A002,
     # A003 class attribute "id" is shadowing a python builtin
     A003,
+    # A005 A module is shadowing a Python builtin module
+    A005,
     # D100 Missing docstring in public module
     D100,
     # D101 Missing docstring in public class
diff --git a/src/aiogram_dialog/widgets/kbd/calendar_kbd.py b/src/aiogram_dialog/widgets/kbd/calendar_kbd.py
index 01af9aaf..a886f347 100644
--- a/src/aiogram_dialog/widgets/kbd/calendar_kbd.py
+++ b/src/aiogram_dialog/widgets/kbd/calendar_kbd.py
@@ -3,7 +3,6 @@
 from dataclasses import dataclass
 from datetime import date, datetime, timedelta, timezone
 from enum import Enum
-from time import mktime
 from typing import (
     Any, Callable, Dict, List, Optional, Protocol, TypedDict, TypeVar, Union,
 )
@@ -20,6 +19,8 @@
 )
 from .base import Keyboard
 
+EPOCH = date(1970, 1, 1)
+
 CALLBACK_NEXT_MONTH = "+"
 CALLBACK_PREV_MONTH = "-"
 CALLBACK_NEXT_YEAR = "+Y"
@@ -63,6 +64,16 @@ class CalendarScope(Enum):
     YEARS = "YEARS"
 
 
+def raw_from_date(d: date) -> int:
+    diff = d - EPOCH
+    raw_date = int(diff.total_seconds())
+    return raw_date
+
+
+def date_from_raw(raw_date: int) -> date:
+    return EPOCH + timedelta(seconds=raw_date)
+
+
 def month_begin(offset: date):
     return offset.replace(day=1)
 
@@ -203,7 +214,9 @@ async def _render_date_button(
             text = self.today_text
         else:
             text = self.date_text
-        raw_date = int(mktime(selected_date.timetuple()))
+
+        raw_date = raw_from_date(selected_date)
+
         return InlineKeyboardButton(
             text=await text.render_text(
                 current_data, manager,
@@ -852,12 +865,11 @@ async def _handle_click_year(
     async def _handle_click_date(
             self, data: str, manager: DialogManager,
     ) -> None:
-        raw_date = int(data)
         await self.on_click.process_event(
             manager.event,
             self.managed(manager),
             manager,
-            date.fromtimestamp(raw_date),
+            date_from_raw(int(data)),
         )
 
     async def _process_item_callback(