diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6cc8fd1c3..b5e8f41b6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -464,6 +464,7 @@ set(TDLIB_SOURCE
   td/telegram/DeviceTokenManager.h
   td/telegram/DhCache.h
   td/telegram/DhConfig.h
+  td/telegram/DialogDate.h
   td/telegram/DialogDb.h
   td/telegram/DialogId.h
   td/telegram/DialogParticipant.h
diff --git a/td/telegram/DialogDate.h b/td/telegram/DialogDate.h
new file mode 100644
index 000000000..49082a1d3
--- /dev/null
+++ b/td/telegram/DialogDate.h
@@ -0,0 +1,70 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+#include "td/telegram/DialogId.h"
+#include "td/telegram/MessageId.h"
+
+#include "td/utils/StringBuilder.h"
+
+#include <functional>
+
+namespace td {
+
+class DialogDate {
+  int64 order;
+  DialogId dialog_id;
+
+ public:
+  DialogDate(int64 order, DialogId dialog_id) : order(order), dialog_id(dialog_id) {
+  }
+
+  bool operator<(const DialogDate &other) const {
+    return order > other.order || (order == other.order && dialog_id.get() > other.dialog_id.get());
+  }
+
+  bool operator<=(const DialogDate &other) const {
+    return order >= other.order && (order != other.order || dialog_id.get() >= other.dialog_id.get());
+  }
+
+  bool operator==(const DialogDate &other) const {
+    return order == other.order && dialog_id == other.dialog_id;
+  }
+
+  bool operator!=(const DialogDate &other) const {
+    return order != other.order || dialog_id != other.dialog_id;
+  }
+
+  int64 get_order() const {
+    return order;
+  }
+  DialogId get_dialog_id() const {
+    return dialog_id;
+  }
+  int32 get_date() const {
+    return static_cast<int32>((order >> 32) & 0x7FFFFFFF);
+  }
+  MessageId get_message_id() const {
+    return MessageId(ServerMessageId(static_cast<int32>(order & 0x7FFFFFFF)));
+  }
+};
+
+const DialogDate MIN_DIALOG_DATE(std::numeric_limits<int64>::max(), DialogId());
+const DialogDate MAX_DIALOG_DATE(0, DialogId());
+const int64 DEFAULT_ORDER = -1;
+
+struct DialogDateHash {
+  std::size_t operator()(const DialogDate &dialog_date) const {
+    return std::hash<int64>()(dialog_date.get_order()) * 2023654985u + DialogIdHash()(dialog_date.get_dialog_id());
+  }
+};
+
+inline StringBuilder &operator<<(StringBuilder &string_builder, DialogDate dialog_date) {
+  return string_builder << "[" << dialog_date.get_order() << ", " << dialog_date.get_dialog_id().get() << "]";
+}
+
+}  // namespace td
diff --git a/td/telegram/MessagesManager.h b/td/telegram/MessagesManager.h
index 1c7a957d7..e20accf31 100644
--- a/td/telegram/MessagesManager.h
+++ b/td/telegram/MessagesManager.h
@@ -21,6 +21,7 @@
 #include "td/telegram/AccessRights.h"
 #include "td/telegram/ChannelId.h"
 #include "td/telegram/Dependencies.h"
+#include "td/telegram/DialogDate.h"
 #include "td/telegram/DialogId.h"
 #include "td/telegram/DialogParticipant.h"
 #include "td/telegram/files/FileId.h"
@@ -65,62 +66,6 @@ class MultiSequenceDispatcher;
 
 class DraftMessage;
 
-class DialogDate {
-  int64 order;
-  DialogId dialog_id;
-
- public:
-  DialogDate(int64 order, DialogId dialog_id) : order(order), dialog_id(dialog_id) {
-  }
-
-  bool operator<(const DialogDate &other) const {
-    return order > other.order || (order == other.order && dialog_id.get() > other.dialog_id.get());
-  }
-
-  bool operator<=(const DialogDate &other) const {
-    return order >= other.order && (order != other.order || dialog_id.get() >= other.dialog_id.get());
-  }
-
-  bool operator==(const DialogDate &other) const {
-    return order == other.order && dialog_id == other.dialog_id;
-  }
-
-  bool operator!=(const DialogDate &other) const {
-    return order != other.order || dialog_id != other.dialog_id;
-  }
-
-  int64 get_order() const {
-    return order;
-  }
-  DialogId get_dialog_id() const {
-    return dialog_id;
-  }
-  int32 get_date() const {
-    return static_cast<int32>((order >> 32) & 0x7FFFFFFF);
-  }
-  MessageId get_message_id() const {
-    return MessageId(ServerMessageId(static_cast<int32>(order & 0x7FFFFFFF)));
-  }
-
-  friend struct DialogDateHash;
-
-  friend StringBuilder &operator<<(StringBuilder &string_builder, DialogDate dialog_date);
-};
-
-const DialogDate MIN_DIALOG_DATE(std::numeric_limits<int64>::max(), DialogId());
-const DialogDate MAX_DIALOG_DATE(0, DialogId());
-const int64 DEFAULT_ORDER = -1;
-
-struct DialogDateHash {
-  std::size_t operator()(const DialogDate &dialog_date) const {
-    return std::hash<int64>()(dialog_date.order) * 2023654985u + DialogIdHash()(dialog_date.dialog_id);
-  }
-};
-
-inline StringBuilder &operator<<(StringBuilder &string_builder, DialogDate dialog_date) {
-  return string_builder << "[" << dialog_date.order << ", " << dialog_date.dialog_id.get() << "]";
-}
-
 class dummyUpdate : public telegram_api::Update {
  public:
   static constexpr int32 ID = 1234567891;