diff --git a/front-end/.gitignore b/front-end/.gitignore
index 714f38e..f5f2ac9 100644
--- a/front-end/.gitignore
+++ b/front-end/.gitignore
@@ -25,4 +25,6 @@ dist-ssr
 
 .env*
 
-*.pem
\ No newline at end of file
+*.pem
+
+vercel*
\ No newline at end of file
diff --git a/front-end/package.json b/front-end/package.json
index 8428f3b..5c0f978 100644
--- a/front-end/package.json
+++ b/front-end/package.json
@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "prebuild": "node copyCmaps.js && node vercelRewrite.js",
+    "prebuild": "node copyCmaps.js",
     "build": "tsc -b && vite build",
     "lint": "eslint .",
     "preview": "vite preview"
diff --git a/front-end/src/pages/professor/home/modal/CourseModal.tsx b/front-end/src/pages/professor/home/modal/CourseModal.tsx
index 5e13a0b..02a3f4e 100644
--- a/front-end/src/pages/professor/home/modal/CourseModal.tsx
+++ b/front-end/src/pages/professor/home/modal/CourseModal.tsx
@@ -54,6 +54,40 @@ const makeFullUniversity = (university: string) => {
   return university;
 };
 
+const checkScheduleError = (schedules: CourseForm['schedule']): boolean => {
+  let isScheduleError = false;
+
+  schedules.forEach((schedule, index) => {
+    if (isScheduleError) return;
+
+    if (schedule.day === '') {
+      isScheduleError = true;
+    }
+    if (!timeRegex.test(schedule.start) || !timeRegex.test(schedule.end)) {
+      isScheduleError = true;
+    }
+    if (schedule.start >= schedule.end) {
+      isScheduleError = true;
+    }
+
+    schedules.forEach((otherSchedule, otherIndex) => {
+      if (isScheduleError) return;
+
+      if (index >= otherIndex) return;
+
+      if (
+        schedule.day === otherSchedule.day &&
+        schedule.start < otherSchedule.end &&
+        schedule.end > otherSchedule.start
+      ) {
+        isScheduleError = true;
+      }
+    });
+  });
+
+  return isScheduleError;
+};
+
 const checkFormError = (
   courseError: CourseError,
   courseForm: CourseForm
@@ -77,22 +111,7 @@ const checkFormError = (
     return true;
   }
 
-  let isScheduleError = false;
-  courseForm.schedule.forEach((schedule) => {
-    if (isScheduleError) return;
-
-    if (schedule.day === '') {
-      isScheduleError = true;
-    }
-    if (!timeRegex.test(schedule.start) || !timeRegex.test(schedule.end)) {
-      isScheduleError = true;
-    }
-    if (schedule.start >= schedule.end) {
-      isScheduleError = true;
-    }
-  });
-
-  return isScheduleError;
+  return checkScheduleError(courseForm.schedule);
 };
 
 const CourseModal = ({ course, onSubmit, onClose }: CourseModalProps) => {
diff --git a/front-end/src/pages/professor/home/modal/components/TimeInput.tsx b/front-end/src/pages/professor/home/modal/components/TimeInput.tsx
index 81dc028..7156398 100644
--- a/front-end/src/pages/professor/home/modal/components/TimeInput.tsx
+++ b/front-end/src/pages/professor/home/modal/components/TimeInput.tsx
@@ -37,11 +37,12 @@ const TimeInput = ({ time, setTime }: TimeInputProps) => {
             setLocalHour('00');
             setTime(`00:${localMinute}`);
           } else if (parseInt(inputHour) > 23) {
+            setLocalHour('23');
             setTime(`23:${localMinute}`);
           } else {
-            setTime(
-              `${parseInt(inputHour).toString().padStart(2, '0')}:${localMinute}`
-            );
+            const parsedHour = parseInt(inputHour).toString().padStart(2, '0');
+            setLocalHour(parsedHour);
+            setTime(`${parsedHour}:${localMinute}`);
           }
         }}
       />
@@ -64,11 +65,14 @@ const TimeInput = ({ time, setTime }: TimeInputProps) => {
             setLocalMinute('00');
             setTime(`${localHour}:00`);
           } else if (parseInt(inputMinute) > 59) {
+            setLocalMinute('59');
             setTime(`${localHour}:59`);
           } else {
-            setTime(
-              `${localHour}:${parseInt(inputMinute).toString().padStart(2, '0')}`
-            );
+            const parsedMinute = parseInt(inputMinute)
+              .toString()
+              .padStart(2, '0');
+            setLocalMinute(parsedMinute);
+            setTime(`${localHour}:${parsedMinute}`);
           }
         }}
       />
diff --git a/front-end/vercel.json b/front-end/vercel.json
deleted file mode 100644
index c1a7308..0000000
--- a/front-end/vercel.json
+++ /dev/null
@@ -1,12 +0,0 @@
-{
-  "rewrites": [
-    {
-      "source": "/api/:path*",
-      "destination": "VITE_API_URL/:path*"
-    },
-    {
-      "source": "/:path((?!api).*)",
-      "destination": "/index.html"
-    }
-  ]
-}
diff --git a/front-end/vercelRewrite.js b/front-end/vercelRewrite.js
deleted file mode 100644
index 88bd9f2..0000000
--- a/front-end/vercelRewrite.js
+++ /dev/null
@@ -1,29 +0,0 @@
-// vercel-prebuild.js
-import fs from 'fs';
-import path from 'path';
-import { fileURLToPath } from 'url';
-
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-
-const apiUrl = process.env.VITE_API_URL;
-if (!apiUrl) {
-  console.error('Error: VITE_API_URL 환경변수가 설정되어 있지 않습니다.');
-  process.exit(1);
-}
-
-const vercelJsonPath = path.join(__dirname, 'vercel.json');
-
-try {
-  // vercel.json 파일 읽기
-  const fileContent = fs.readFileSync(vercelJsonPath, 'utf8');
-
-  // 파일 내의 모든 "VITE_API_URL" 문자열을 실제 환경변수 값으로 치환
-  const updatedContent = fileContent.replace(/VITE_API_URL/g, apiUrl);
-
-  // 치환된 내용을 다시 vercel.json 파일에 기록
-  fs.writeFileSync(vercelJsonPath, updatedContent, 'utf8');
-  console.log('vercel.json 파일이 성공적으로 업데이트되었습니다.');
-} catch (error) {
-  console.error('vercel.json 파일 처리 중 에러 발생:', error);
-  process.exit(1);
-}