diff --git a/index.html b/index.html
index a589c03..6563706 100644
--- a/index.html
+++ b/index.html
@@ -6,6 +6,11 @@
       name="viewport"
       content="width=device-width, initial-scale=1, maximum-scale=1, shrink-to-fit=no, viewport-fit=cover" />
     <meta name="theme-color" content="#F9F0F0" />
+    <meta property="og:title" content="OTL - Online Timetable with Lectures" />
+    <meta property="og:description" content="카이스트 학생들을 위한 시간표 서비스입니다" />
+    <meta property="og:type" content="website" />
+    <meta property="og:site_name" content="OTL" />
+    <meta property="og:image" content="https://otl.kaist.ac.kr/static/favicon-192.png" />
     <!--
       manifest.json provides metadata used when your web app is added to the
       homescreen on Android. See https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/
diff --git a/src/components/sections/main/TodaysTimetableSection.jsx b/src/components/sections/main/TodaysTimetableSection.jsx
index 3d9a19f..aaed42d 100644
--- a/src/components/sections/main/TodaysTimetableSection.jsx
+++ b/src/components/sections/main/TodaysTimetableSection.jsx
@@ -7,7 +7,7 @@ import queryString from 'qs';
 import { range } from 'lodash';
 
 import { appBoundClassNames as classNames } from '../../../common/boundClassNames';
-import { TIMETABLE_START_HOUR, TIMETABLE_END_HOUR } from '../../../common/constants';
+import { TIMETABLE_END_HOUR, TIMETABLE_START_HOUR } from '../../../common/constants';
 
 import Scroller from '../../Scroller';
 
@@ -89,8 +89,7 @@ class TodaysTimetableSection extends Component {
     const { cellWidth, cellHeight, now } = this.state;
     const { user, semesters, currentSemester } = this.props;
 
-    const ongoingSemester =
-      currentSemester || (semesters ? getOngoingSemester(semesters) : undefined);
+    const ongoingSemester = semesters ? getOngoingSemester(semesters) : undefined;
     const lectures =
       user && ongoingSemester
         ? user.my_timetable_lectures.filter(
diff --git a/src/redux/actions/common/semester.ts b/src/redux/actions/common/semester.ts
index 4498455..3624cc6 100644
--- a/src/redux/actions/common/semester.ts
+++ b/src/redux/actions/common/semester.ts
@@ -5,6 +5,12 @@ export const SET_CURRENT_SEMESTER = `${BASE_STRING}SET_CURRENT_SEMESTER` as cons
 
 import Semester from '@/shapes/model/subject/Semester';
 
+/**
+ * Creates an action to set the list of semesters in the state.
+ *
+ * @param semesters - The array of Semester objects to set
+ * @returns An action object with type SET_SEMESTERS and the semesters payload
+ */
 export function setSemesters(semesters: Semester[]) {
   return {
     type: SET_SEMESTERS,
@@ -12,6 +18,12 @@ export function setSemesters(semesters: Semester[]) {
   };
 }
 
+/**
+ * Creates an action to set the current semester in the state.
+ *
+ * @param semester - The semester to be set as current
+ * @returns An action object with type `SET_CURRENT_SEMESTER` and the specified semester
+ */
 export function setCurrentSemester(semester: Semester) {
   return {
     type: SET_CURRENT_SEMESTER,