diff --git a/www/__tests__/DateSelect.test.tsx b/www/__tests__/DateSelect.test.tsx
index 29a6d7162..e66424f17 100644
--- a/www/__tests__/DateSelect.test.tsx
+++ b/www/__tests__/DateSelect.test.tsx
@@ -3,6 +3,8 @@ import { render, screen, fireEvent, waitFor } from '@testing-library/react-nativ
 import DateSelect from '../js/diary/list/DateSelect';
 import { DateTime } from 'luxon';
 import TimelineContext from '../js/TimelineContext';
+import initializedI18next from '../js/i18nextInit';
+window['i18next'] = initializedI18next;
 
 jest.mock('react-native-safe-area-context', () => ({
   useSafeAreaInsets: () => ({ bottom: 30, left: 0, right: 0, top: 30 }),
@@ -17,12 +19,16 @@ jest.mock('react', () => ({
 describe('DateSelect', () => {
   const pipelineRangeMock = {
     start_ts: DateTime.local().set({ month: 5, day: 20 }).startOf('day').toSeconds(),
-    end_ts: DateTime.local().set({ month: 5, day: 30 }).endOf('day').toSeconds(),
+    end_ts: DateTime.local()
+      .set({ month: 5, day: 30 })
+      .endOf('day')
+      .set({ millisecond: 0 })
+      .toSeconds(),
   };
 
   const queriedDateRangeMock = [
     DateTime.local().set({ month: 5, day: 20 }).startOf('day').toISO(),
-    DateTime.local().set({ month: 5, day: 30 }).endOf('day').toISO(),
+    DateTime.local().set({ month: 5, day: 30 }).endOf('day').set({ millisecond: 0 }).toISO(),
   ];
 
   const contextValue = {
@@ -30,7 +36,7 @@ describe('DateSelect', () => {
     queriedDateRange: queriedDateRangeMock,
   };
 
-  it('renders correctly DatePickerModal after clicking the button', async () => {
+  it('renders correctly DatePickerModal after clicking the button and save date correctly', async () => {
     const onChooseMock = jest.fn();
     render(
       <TimelineContext.Provider value={contextValue}>
@@ -49,5 +55,27 @@ describe('DateSelect', () => {
       expect(screen.getByTestId('react-native-paper-dates-close')).toBeTruthy();
       expect(screen.getByTestId('react-native-paper-dates-save-text')).toBeTruthy();
     });
+
+    // check if date changes corretly
+    // Start Date : 05/20/24 -> 05/25/2024
+    fireEvent.changeText(screen.getAllByTestId('text-input-flat')[0], '05/25/2024');
+    expect(screen.queryByDisplayValue('May 20')).toBeNull();
+    expect(screen.getByText('May 25')).toBeTruthy();
+    // End Date : 05/30/24 -> 05/28/2024
+    fireEvent.changeText(screen.getAllByTestId('text-input-flat')[1], '05/28/2024');
+    expect(screen.queryByDisplayValue('May 30')).toBeNull();
+    expect(screen.getByText('May 28')).toBeTruthy();
+
+    // check if onChoose function gets called with changed dates after clicking 'save' button.
+    fireEvent.press(screen.getByTestId('react-native-paper-dates-save-text'));
+    const expectedParams = {
+      startDate: DateTime.local().set({ month: 5, day: 25 }).startOf('day').toJSDate(),
+      endDate: DateTime.local()
+        .set({ month: 5, day: 28 })
+        .endOf('day')
+        .set({ millisecond: 0 })
+        .toJSDate(),
+    };
+    expect(onChooseMock).toHaveBeenCalledWith(expectedParams);
   });
 });