diff --git a/dist/index.js b/dist/index.js
index 37e78682..801bdafd 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1365,6 +1365,192 @@
     }
   };
 
+  // src/View/utility.ts
+  function allowDrop(event) {
+    event.preventDefault();
+  }
+  function allowDrag(event) {
+    event.dataTransfer?.setData("text", "");
+  }
+
+  // src/ViewModel/Pages/taskViewModel.ts
+  var TaskViewModel = class {
+    // init
+    constructor(coreViewModel, boardsAndTasksModel, boardViewModel, calendarPageViewModel, taskFileContent) {
+      this.coreViewModel = coreViewModel;
+      this.boardsAndTasksModel = boardsAndTasksModel;
+      this.boardViewModel = boardViewModel;
+      this.calendarPageViewModel = calendarPageViewModel;
+      this.task = taskFileContent;
+      this.loadAllData();
+      this.selectedVersionId.subscribeSilent((selectedVersionId) => {
+        this.switchVersion(selectedVersionId);
+      });
+    }
+    boardsAndTasksModel;
+    boardViewModel;
+    calendarPageViewModel;
+    // data
+    task;
+    get sortingString() {
+      const splitDate = this.date.value.split("-");
+      const year = padZero(splitDate[0], 4);
+      const month = padZero(splitDate[1], 2);
+      const date = padZero(splitDate[2], 2);
+      const splitTime = this.time.value.split(":");
+      const hour = padZero(splitTime[0], 2);
+      const minute = padZero(splitTime[1], 2);
+      const priorityNumber = parseInt(this.priority.value);
+      const invertedPriority = 100 - priorityNumber;
+      return year + month + date + hour + minute + invertedPriority + this.name.value;
+    }
+    // paths
+    getFilePath = () => {
+      return this.boardsAndTasksModel.getTaskFilePath(this.task.fileId);
+    };
+    // state
+    index = new State(0);
+    boardId = new State("");
+    name = new State("");
+    description = new State("");
+    category = new State("");
+    status = new State("");
+    priority = new State("");
+    date = new State("");
+    time = new State("");
+    selectedVersionId = new State("");
+    versionIds = new ListState();
+    // methods
+    dragStart = (event) => {
+      allowDrag(event);
+      this.coreViewModel.draggedObject.value = this;
+    };
+    setCategoryAndStatus = (category, status) => {
+      if (category != void 0) this.category.value = category;
+      if (status != void 0) this.status.value = status;
+      this.save();
+    };
+    setBoardId = (boardId) => {
+      this.boardId.value = boardId;
+      this.save();
+    };
+    // view
+    open = () => {
+      this.boardViewModel?.selectTask(this);
+    };
+    close = () => {
+      this.boardViewModel?.closeTask();
+    };
+    closeAndSave = () => {
+      this.close();
+      this.save();
+    };
+    updateIndex = () => {
+      if (this.boardViewModel == null) return;
+      const index = this.boardViewModel.taskIndexManager.getIndex(this);
+      this.index.value = index;
+    };
+    // settings
+    save = () => {
+      const newTaskFileContent = BoardsAndTasksModel.createTaskFileContent(
+        this.task.fileId,
+        this.name.value,
+        this.task.boardId
+      );
+      newTaskFileContent.boardId = this.boardId.value;
+      newTaskFileContent.description = this.description.value;
+      newTaskFileContent.status = this.status.value;
+      newTaskFileContent.category = this.category.value;
+      newTaskFileContent.priority = this.priority.value;
+      newTaskFileContent.date = this.date.value;
+      newTaskFileContent.time = this.time.value;
+      this.boardsAndTasksModel.updateTaskAndSend(newTaskFileContent);
+      if (this.boardViewModel != null) {
+        this.boardViewModel.showTaskInList(newTaskFileContent);
+        this.boardViewModel.updateTaskIndices();
+      }
+      if (this.calendarPageViewModel != null) {
+      }
+    };
+    deleteTask = () => {
+      this.close();
+      this.boardsAndTasksModel.deleteTask(this.task.boardId, this.task.fileId);
+      if (this.boardViewModel != null) {
+        this.boardViewModel.removeTaskFromList(this.task.fileId);
+      }
+      if (this.calendarPageViewModel != null) {
+      }
+    };
+    // load
+    loadVersionIds = () => {
+      const versionIds = this.boardsAndTasksModel.listTaskVersionIds(
+        this.task.fileId
+      );
+      const sortedVersionIds = versionIds.sort(localeCompare).reverse();
+      this.versionIds.clear();
+      this.versionIds.add(...sortedVersionIds);
+    };
+    switchVersion = (versionId) => {
+      const taskFileContent = this.boardsAndTasksModel.getSpecificTaskFileContent(
+        this.task.fileId,
+        versionId
+      );
+      if (taskFileContent == null) return;
+      this.task = taskFileContent;
+      this.loadTaskData();
+    };
+    loadAllData = () => {
+      this.loadTaskData();
+      this.loadVersionIds();
+    };
+    loadTaskData = () => {
+      this.boardId.value = this.task.boardId;
+      this.name.value = this.task.name;
+      this.description.value = this.task.description ?? "";
+      this.category.value = this.task.category ?? "";
+      this.status.value = this.task.status ?? "";
+      this.priority.value = this.task.priority ?? "";
+      this.date.value = this.task.date ?? "";
+      this.time.value = this.task.time ?? "";
+      this.selectedVersionId.value = this.task.fileContentId;
+    };
+  };
+
+  // src/ViewModel/Pages/calendarPageViewModel.ts
+  var CalendarPageViewModel = class {
+    // init
+    constructor(coreViewModel, storageModel2, calendarModel, boardAndTasksModel) {
+      this.coreViewModel = coreViewModel;
+      this.storageModel = storageModel2;
+      this.calendarModel = calendarModel;
+      this.boardAndTasksModel = boardAndTasksModel;
+    }
+    storageModel;
+    calendarModel;
+    boardAndTasksModel;
+    // paths
+    getBasePath = () => {
+      return [...this.calendarModel.getViewPath()];
+    };
+    // state
+    taskViewModels = new MapState();
+    // view
+    showTask = (taskFileContent) => {
+      const taskViewModel = new TaskViewModel(
+        this.coreViewModel,
+        this.boardAndTasksModel,
+        null,
+        this,
+        taskFileContent
+      );
+      this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
+    };
+    // storage
+    // load
+    loadData = () => {
+    };
+  };
+
   // src/ViewModel/Chat/chatMessageViewModel.ts
   var ChatMessageViewModel = class {
     // init
@@ -1562,146 +1748,6 @@
     };
   };
 
-  // src/View/utility.ts
-  function allowDrop(event) {
-    event.preventDefault();
-  }
-  function allowDrag(event) {
-    event.dataTransfer?.setData("text", "");
-  }
-
-  // src/ViewModel/Pages/taskViewModel.ts
-  var TaskViewModel = class {
-    // init
-    constructor(coreViewModel, boardModel, boardViewModel, taskFileContent) {
-      this.coreViewModel = coreViewModel;
-      this.boardsAndTasksModel = boardModel;
-      this.boardViewModel = boardViewModel;
-      this.task = taskFileContent;
-      this.loadAllData();
-      this.selectedVersionId.subscribeSilent((selectedVersionId) => {
-        this.switchVersion(selectedVersionId);
-      });
-    }
-    boardsAndTasksModel;
-    boardViewModel;
-    // data
-    task;
-    get sortingString() {
-      const splitDate = this.date.value.split("-");
-      const year = padZero(splitDate[0], 4);
-      const month = padZero(splitDate[1], 2);
-      const date = padZero(splitDate[2], 2);
-      const splitTime = this.time.value.split(":");
-      const hour = padZero(splitTime[0], 2);
-      const minute = padZero(splitTime[1], 2);
-      const priorityNumber = parseInt(this.priority.value);
-      const invertedPriority = 100 - priorityNumber;
-      return year + month + date + hour + minute + invertedPriority + this.name.value;
-    }
-    // paths
-    getFilePath = () => {
-      return this.boardsAndTasksModel.getTaskFilePath(this.task.fileId);
-    };
-    // state
-    index = new State(0);
-    boardId = new State("");
-    name = new State("");
-    description = new State("");
-    category = new State("");
-    status = new State("");
-    priority = new State("");
-    date = new State("");
-    time = new State("");
-    selectedVersionId = new State("");
-    versionIds = new ListState();
-    // methods
-    dragStart = (event) => {
-      allowDrag(event);
-      this.coreViewModel.draggedObject.value = this;
-    };
-    setCategoryAndStatus = (category, status) => {
-      if (category != void 0) this.category.value = category;
-      if (status != void 0) this.status.value = status;
-      this.save();
-    };
-    setBoardId = (boardId) => {
-      this.boardId.value = boardId;
-      this.save();
-    };
-    // view
-    open = () => {
-      this.boardViewModel.selectTask(this);
-    };
-    close = () => {
-      this.boardViewModel.closeTask();
-    };
-    closeAndSave = () => {
-      this.close();
-      this.save();
-    };
-    updateIndex = () => {
-      const index = this.boardViewModel.taskIndexManager.getIndex(this);
-      this.index.value = index;
-    };
-    // settings
-    save = () => {
-      const newTaskFileContent = BoardsAndTasksModel.createTaskFileContent(
-        this.task.fileId,
-        this.name.value,
-        this.task.boardId
-      );
-      newTaskFileContent.boardId = this.boardId.value;
-      newTaskFileContent.description = this.description.value;
-      newTaskFileContent.status = this.status.value;
-      newTaskFileContent.category = this.category.value;
-      newTaskFileContent.priority = this.priority.value;
-      newTaskFileContent.date = this.date.value;
-      newTaskFileContent.time = this.time.value;
-      this.boardsAndTasksModel.updateTaskAndSend(newTaskFileContent);
-      this.boardViewModel.showTaskInList(newTaskFileContent);
-      this.boardViewModel.updateTaskIndices();
-    };
-    deleteTask = () => {
-      this.close();
-      this.boardsAndTasksModel.deleteTask(this.task.boardId, this.task.fileId);
-      this.boardViewModel.removeTaskFromList(this.task.fileId);
-    };
-    // load
-    loadVersionIds = () => {
-      const versionIds = this.boardsAndTasksModel.listTaskVersionIds(
-        this.task.fileId
-      );
-      const sortedVersionIds = versionIds.sort(localeCompare).reverse();
-      this.versionIds.clear();
-      this.versionIds.add(...sortedVersionIds);
-    };
-    switchVersion = (versionId) => {
-      const taskFileContent = this.boardsAndTasksModel.getSpecificTaskFileContent(
-        this.task.fileId,
-        versionId
-      );
-      if (taskFileContent == null) return;
-      this.task = taskFileContent;
-      this.loadTaskData();
-    };
-    loadAllData = () => {
-      this.loadTaskData();
-      this.loadVersionIds();
-    };
-    loadTaskData = () => {
-      this.boardId.value = this.task.boardId;
-      this.name.value = this.task.name;
-      this.description.value = this.task.description ?? "";
-      this.category.value = this.task.category ?? "";
-      this.status.value = this.task.status ?? "";
-      this.priority.value = this.task.priority ?? "";
-      this.date.value = this.task.date ?? "";
-      this.time.value = this.task.time ?? "";
-      this.selectedVersionId.value = this.task.fileContentId;
-    };
-  };
-
   // src/ViewModel/Pages/boardViewModel.ts
   var BoardViewModel = class {
     // init
@@ -1782,6 +1828,7 @@
         this.coreViewModel,
         this.boardsAndTasksModel,
         this,
+        null,
         taskFileContent
       );
       this.selectTask(taskViewModel);
@@ -1827,6 +1874,7 @@
         this.coreViewModel,
         this.boardsAndTasksModel,
         this,
+        null,
         taskFileContent
       );
       this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
@@ -1896,6 +1944,7 @@
           this.coreViewModel,
           this.boardsAndTasksModel,
           this,
+          null,
           taskFileContent
         );
         this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
@@ -1914,7 +1963,7 @@
     constructor(coreViewModel, storageModel2, boardModel, chatViewModel) {
       this.coreViewModel = coreViewModel;
       this.storageModel = storageModel2;
-      this.boardModel = boardModel;
+      this.boardsAndTasksModel = boardModel;
       this.chatViewModel = chatViewModel;
       boardModel.boardHandlerManager.addHandler(
         (boardInfoFileContent) => {
@@ -1924,7 +1973,7 @@
       );
     }
     storageModel;
-    boardModel;
+    boardsAndTasksModel;
     chatViewModel;
     // data
     boardIndexManager = new IndexManager(
@@ -1932,7 +1981,7 @@
     );
     // paths
     getBasePath = () => {
-      return [...this.boardModel.getViewPath()];
+      return [...this.boardsAndTasksModel.getViewPath()];
     };
     getBoardViewPath = (boardId) => {
       return [...this.getBasePath(), boardId];
@@ -1952,18 +2001,18 @@
     // methods
     createBoard = () => {
       if (this.cannotCreateBoard.value == true) return;
-      const boardInfoFileContent = this.boardModel.createBoard(this.newBoardNameInput.value);
+      const boardInfoFileContent = this.boardsAndTasksModel.createBoard(this.newBoardNameInput.value);
       this.newBoardNameInput.value = "";
       this.showBoardInList(boardInfoFileContent);
-      this.boardModel.updateBoardAndSend(boardInfoFileContent);
+      this.boardsAndTasksModel.updateBoardAndSend(boardInfoFileContent);
       this.updateBoardIndices();
     };
     updateBoard = (boardInfoFileContent) => {
-      this.boardModel.updateBoardAndSend(boardInfoFileContent);
+      this.boardsAndTasksModel.updateBoardAndSend(boardInfoFileContent);
       this.updateBoardIndices();
     };
     deleteBoard = (boardInfoFileContent) => {
-      this.boardModel.deleteBoard(boardInfoFileContent.fileId);
+      this.boardsAndTasksModel.deleteBoard(boardInfoFileContent.fileId);
       this.boardViewModels.remove(boardInfoFileContent.fileId);
       this.updateBoardIndices();
     };
@@ -1972,7 +2021,7 @@
       const boardViewModel = new BoardViewModel(
         this.coreViewModel,
         this.storageModel,
-        this.boardModel,
+        this.boardsAndTasksModel,
         this,
         boardInfo
       );
@@ -2011,9 +2060,9 @@
     // load
     loadData = () => {
       this.boardViewModels.clear();
-      const boardIds = this.boardModel.listBoardIds();
+      const boardIds = this.boardsAndTasksModel.listBoardIds();
       for (const boardId of boardIds) {
-        const boardInfo = this.boardModel.getBoardInfo(boardId);
+        const boardInfo = this.boardsAndTasksModel.getBoardInfo(boardId);
         if (boardInfo == null) continue;
         this.showBoardInList(boardInfo);
       }
@@ -2031,6 +2080,12 @@
       this.chatModel = chatModel;
       this.settingsViewModel = settingsViewModel2;
       this.chatListViewModel = chatListViewModel2;
+      this.calendarViewModel = new CalendarPageViewModel(
+        coreViewModel,
+        this.storageModel,
+        this.chatModel.fileModel.calendarModel,
+        this.chatModel.fileModel.boardsAndTasksModel
+      );
       this.taskPageViewModel = new TaskPageViewModel(
         this.coreViewModel,
         this.storageModel,
@@ -2057,6 +2112,7 @@
     storageModel;
     settingsViewModel;
     chatListViewModel;
+    calendarViewModel;
     taskPageViewModel;
     messagePageViewModel;
     settingsPageViewModel;
@@ -2182,6 +2238,12 @@
     };
   };
 
+  // src/View/ChatPages/calendarPage.tsx
+  function CalendarPage(calendarPageViewModel) {
+    calendarPageViewModel.loadData();
+    return /* @__PURE__ */ createElement("div", { id: "calendar-page" });
+  }
+
   // src/View/Components/ribbonButton.tsx
   function RibbonButton(label, icon, isSelected, select) {
     return /* @__PURE__ */ createElement(
@@ -3319,6 +3381,9 @@
           case "tasks" /* Tasks */: {
             return TaskPage(chatViewModel.taskPageViewModel);
           }
+          case "calendar" /* Calendar */: {
+            return CalendarPage(chatViewModel.calendarViewModel);
+          }
           default: {
             return MessagePage(chatViewModel.messagePageViewModel);
           }
diff --git a/src/View/ChatPages/calendarPage.tsx b/src/View/ChatPages/calendarPage.tsx
new file mode 100644
index 00000000..4071f663
--- /dev/null
+++ b/src/View/ChatPages/calendarPage.tsx
@@ -0,0 +1,9 @@
+import * as React from "bloatless-react";
+
+import CalendarPageViewModel from "../../ViewModel/Pages/calendarPageViewModel";
+
+export function CalendarPage(calendarPageViewModel: CalendarPageViewModel) {
+  calendarPageViewModel.loadData();
+
+  return <div id="calendar-page"></div>;
+}
diff --git a/src/View/chatPage.tsx b/src/View/chatPage.tsx
index 985ea43a..e84b62ec 100644
--- a/src/View/chatPage.tsx
+++ b/src/View/chatPage.tsx
@@ -4,6 +4,7 @@ import * as React from "bloatless-react";
 
 import ChatViewModel, { ChatPageType } from "../ViewModel/Chat/chatViewModel";
 
+import { CalendarPage } from "./ChatPages/calendarPage";
 import { ChatViewToggleButton } from "./Components/chatViewToggleButton";
 import { MessagePage } from "./ChatPages/messagePage";
 import { SettingsPage } from "./ChatPages/settingsPage";
@@ -23,6 +24,9 @@ export function ChatPage(chatViewModel: ChatViewModel) {
         case ChatPageType.Tasks: {
           return TaskPage(chatViewModel.taskPageViewModel);
         }
+        case ChatPageType.Calendar: {
+          return CalendarPage(chatViewModel.calendarViewModel)
+        }
         default: {
           return MessagePage(chatViewModel.messagePageViewModel);
         }
diff --git a/src/ViewModel/Chat/chatViewModel.ts b/src/ViewModel/Chat/chatViewModel.ts
index b3677970..33c59d9e 100644
--- a/src/ViewModel/Chat/chatViewModel.ts
+++ b/src/ViewModel/Chat/chatViewModel.ts
@@ -1,8 +1,12 @@
 import * as React from "bloatless-react";
 
 import ChatModel, { ChatMessage } from "../../Model/Chat/chatModel";
-import StorageModel, { StorageModelSubPath, filePaths } from "../../Model/Global/storageModel";
+import StorageModel, {
+  StorageModelSubPath,
+  filePaths,
+} from "../../Model/Global/storageModel";
 
+import CalendarPageViewModel from "../Pages/calendarPageViewModel";
 import ChatListViewModel from "./chatListViewModel";
 import { Color } from "../../colors";
 import CoreViewModel from "../Global/coreViewModel";
@@ -17,6 +21,7 @@ export default class ChatViewModel {
   settingsViewModel: SettingsViewModel;
   chatListViewModel: ChatListViewModel;
 
+  calendarViewModel: CalendarPageViewModel;
   taskPageViewModel: TaskPageViewModel;
   messagePageViewModel: MessagePageViewModel;
   settingsPageViewModel: SettingsPageViewModel;
@@ -91,6 +96,12 @@ export default class ChatViewModel {
     this.chatListViewModel = chatListViewModel;
 
     // page viewModels
+    this.calendarViewModel = new CalendarPageViewModel(
+      coreViewModel,
+      this.storageModel,
+      this.chatModel.fileModel.calendarModel,
+      this.chatModel.fileModel.boardsAndTasksModel
+    );
     this.taskPageViewModel = new TaskPageViewModel(
       this.coreViewModel,
       this.storageModel,
diff --git a/src/ViewModel/Pages/boardViewModel.ts b/src/ViewModel/Pages/boardViewModel.ts
index 577337e6..57a3cfec 100644
--- a/src/ViewModel/Pages/boardViewModel.ts
+++ b/src/ViewModel/Pages/boardViewModel.ts
@@ -82,6 +82,7 @@ export default class BoardViewModel {
       this.coreViewModel,
       this.boardsAndTasksModel,
       this,
+      null,
       taskFileContent
     );
     this.selectTask(taskViewModel);
@@ -136,6 +137,7 @@ export default class BoardViewModel {
       this.coreViewModel,
       this.boardsAndTasksModel,
       this,
+      null,
       taskFileContent
     );
     this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
@@ -222,6 +224,7 @@ export default class BoardViewModel {
         this.coreViewModel,
         this.boardsAndTasksModel,
         this,
+        null,
         taskFileContent
       );
       this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
diff --git a/src/ViewModel/Pages/calendarPageViewModel.ts b/src/ViewModel/Pages/calendarPageViewModel.ts
new file mode 100644
index 00000000..aacc434e
--- /dev/null
+++ b/src/ViewModel/Pages/calendarPageViewModel.ts
@@ -0,0 +1,57 @@
+import * as React from "bloatless-react";
+
+import BoardsAndTasksModel, {
+  TaskFileContent,
+} from "../../Model/Files/boardsAndTasksModel";
+
+import CalendarModel from "../../Model/Files/calendarModel";
+import CoreViewModel from "../Global/coreViewModel";
+import StorageModel from "../../Model/Global/storageModel";
+import TaskViewModel from "./taskViewModel";
+
+export default class CalendarPageViewModel {
+  storageModel: StorageModel;
+  calendarModel: CalendarModel;
+  boardAndTasksModel: BoardsAndTasksModel;
+
+  // paths
+  getBasePath = (): string[] => {
+    return [...this.calendarModel.getViewPath()];
+  };
+
+  // state
+  taskViewModels: React.MapState<TaskViewModel> = new React.MapState();
+
+  // view
+  showTask = (taskFileContent: TaskFileContent): void => {
+    const taskViewModel: TaskViewModel = new TaskViewModel(
+      this.coreViewModel,
+      this.boardAndTasksModel,
+      null,
+      this,
+      taskFileContent
+    );
+    this.taskViewModels.set(taskFileContent.fileId, taskViewModel);
+  };
+
+  // storage
+
+  // load
+  loadData = (): void => {}
+
+  // init
+  constructor(
+    public coreViewModel: CoreViewModel,
+    storageModel: StorageModel,
+    calendarModel: CalendarModel,
+    boardAndTasksModel: BoardsAndTasksModel,
+  ) {
+    this.storageModel = storageModel;
+    this.calendarModel = calendarModel;
+    this.boardAndTasksModel = boardAndTasksModel;
+  }
+}
+
+export enum TaskPageViewModelSubPath {
+  LastUsedBoard = "last-used-board",
+}
diff --git a/src/ViewModel/Pages/taskPageViewModel.ts b/src/ViewModel/Pages/taskPageViewModel.ts
index ff20a1d1..ccb52f37 100644
--- a/src/ViewModel/Pages/taskPageViewModel.ts
+++ b/src/ViewModel/Pages/taskPageViewModel.ts
@@ -9,11 +9,10 @@ import ChatViewModel from "../Chat/chatViewModel";
 import CoreViewModel from "../Global/coreViewModel";
 import { IndexManager } from "../../Model/Utility/utility";
 import StorageModel from "../../Model/Global/storageModel";
-import TaskViewModel from "./taskViewModel";
 
 export default class TaskPageViewModel {
   storageModel: StorageModel;
-  boardModel: BoardsAndTasksModel;
+  boardsAndTasksModel: BoardsAndTasksModel;
 
   chatViewModel: ChatViewModel;
 
@@ -24,7 +23,7 @@ export default class TaskPageViewModel {
 
   // paths
   getBasePath = (): string[] => {
-    return [...this.boardModel.getViewPath()];
+    return [...this.boardsAndTasksModel.getViewPath()];
   };
 
   getBoardViewPath = (boardId): string[] => {
@@ -55,21 +54,21 @@ export default class TaskPageViewModel {
     if (this.cannotCreateBoard.value == true) return;
 
     const boardInfoFileContent: BoardInfoFileContent =
-      this.boardModel.createBoard(this.newBoardNameInput.value);
+      this.boardsAndTasksModel.createBoard(this.newBoardNameInput.value);
     this.newBoardNameInput.value = "";
 
     this.showBoardInList(boardInfoFileContent);
-    this.boardModel.updateBoardAndSend(boardInfoFileContent);
+    this.boardsAndTasksModel.updateBoardAndSend(boardInfoFileContent);
     this.updateBoardIndices();
   };
 
   updateBoard = (boardInfoFileContent: BoardInfoFileContent): void => {
-    this.boardModel.updateBoardAndSend(boardInfoFileContent);
+    this.boardsAndTasksModel.updateBoardAndSend(boardInfoFileContent);
     this.updateBoardIndices();
   };
 
   deleteBoard = (boardInfoFileContent: BoardInfoFileContent): void => {
-    this.boardModel.deleteBoard(boardInfoFileContent.fileId);
+    this.boardsAndTasksModel.deleteBoard(boardInfoFileContent.fileId);
     this.boardViewModels.remove(boardInfoFileContent.fileId);
     this.updateBoardIndices();
   };
@@ -79,7 +78,7 @@ export default class TaskPageViewModel {
     const boardViewModel: BoardViewModel = new BoardViewModel(
       this.coreViewModel,
       this.storageModel,
-      this.boardModel,
+      this.boardsAndTasksModel,
       this,
       boardInfo
     );
@@ -130,10 +129,10 @@ export default class TaskPageViewModel {
   loadData = (): void => {
     this.boardViewModels.clear();
 
-    const boardIds: string[] = this.boardModel.listBoardIds();
+    const boardIds: string[] = this.boardsAndTasksModel.listBoardIds();
     for (const boardId of boardIds) {
       const boardInfo: BoardInfoFileContent | null =
-        this.boardModel.getBoardInfo(boardId);
+        this.boardsAndTasksModel.getBoardInfo(boardId);
       if (boardInfo == null) continue;
 
       this.showBoardInList(boardInfo);
@@ -151,7 +150,7 @@ export default class TaskPageViewModel {
     chatViewModel: ChatViewModel
   ) {
     this.storageModel = storageModel;
-    this.boardModel = boardModel;
+    this.boardsAndTasksModel = boardModel;
 
     this.chatViewModel = chatViewModel;
 
diff --git a/src/ViewModel/Pages/taskViewModel.ts b/src/ViewModel/Pages/taskViewModel.ts
index 43d86a7b..76538f85 100644
--- a/src/ViewModel/Pages/taskViewModel.ts
+++ b/src/ViewModel/Pages/taskViewModel.ts
@@ -6,13 +6,15 @@ import BoardsAndTasksModel, {
 import { localeCompare, padZero } from "../../Model/Utility/utility";
 
 import BoardViewModel from "./boardViewModel";
+import CalendarPageViewModel from "./calendarPageViewModel";
 import CoreViewModel from "../Global/coreViewModel";
 import { allowDrag } from "../../View/utility";
 
 export default class TaskViewModel {
   boardsAndTasksModel: BoardsAndTasksModel;
 
-  boardViewModel: BoardViewModel;
+  boardViewModel: BoardViewModel | null;
+  calendarPageViewModel: CalendarPageViewModel | null;
 
   // data
   task: TaskFileContent;
@@ -77,11 +79,11 @@ export default class TaskViewModel {
 
   // view
   open = (): void => {
-    this.boardViewModel.selectTask(this);
+    this.boardViewModel?.selectTask(this);
   };
 
   close = (): void => {
-    this.boardViewModel.closeTask();
+    this.boardViewModel?.closeTask();
   };
 
   closeAndSave = (): void => {
@@ -90,6 +92,7 @@ export default class TaskViewModel {
   };
 
   updateIndex = (): void => {
+    if (this.boardViewModel == null) return;
     const index: number = this.boardViewModel.taskIndexManager.getIndex(this);
     this.index.value = index;
   };
@@ -112,14 +115,24 @@ export default class TaskViewModel {
     newTaskFileContent.time = this.time.value;
 
     this.boardsAndTasksModel.updateTaskAndSend(newTaskFileContent);
-    this.boardViewModel.showTaskInList(newTaskFileContent);
-    this.boardViewModel.updateTaskIndices();
+
+    if (this.boardViewModel != null) {
+      this.boardViewModel.showTaskInList(newTaskFileContent);
+      this.boardViewModel.updateTaskIndices();
+    }
+    if (this.calendarPageViewModel != null) {
+    }
   };
 
   deleteTask = (): void => {
     this.close();
     this.boardsAndTasksModel.deleteTask(this.task.boardId, this.task.fileId);
-    this.boardViewModel.removeTaskFromList(this.task.fileId);
+
+    if (this.boardViewModel != null) {
+      this.boardViewModel.removeTaskFromList(this.task.fileId);
+    }
+    if (this.calendarPageViewModel != null) {
+    }
   };
 
   // load
@@ -168,12 +181,14 @@ export default class TaskViewModel {
   // init
   constructor(
     public coreViewModel: CoreViewModel,
-    boardModel: BoardsAndTasksModel,
-    boardViewModel: BoardViewModel,
+    boardsAndTasksModel: BoardsAndTasksModel,
+    boardViewModel: BoardViewModel | null,
+    calendarPageViewModel: CalendarPageViewModel | null,
     taskFileContent: TaskFileContent
   ) {
-    this.boardsAndTasksModel = boardModel;
+    this.boardsAndTasksModel = boardsAndTasksModel;
     this.boardViewModel = boardViewModel;
+    this.calendarPageViewModel = calendarPageViewModel;
 
     this.task = taskFileContent;