diff --git a/frontend/__test__/calculateDeadlineTime.test.ts b/frontend/__test__/calculateDeadlineTime.test.ts
index c1e7074ac..f7f4b29c7 100644
--- a/frontend/__test__/calculateDeadlineTime.test.ts
+++ b/frontend/__test__/calculateDeadlineTime.test.ts
@@ -65,4 +65,30 @@ describe('calculateDeadlineTime 함수를 이용해서 시작시간과 마감시
       minute: 59,
     });
   });
+
+  test('시작 시간이 undefined, 마감 시간: 2023-07-14 23:59 일 때 0일 0시간 0분을 반환한다.', () => {
+    const createdAt = undefined;
+    const deadline = '2023-07-14 23:59';
+
+    const result = calculateDeadlineTime(createdAt, deadline);
+
+    expect(result).toEqual({
+      day: 0,
+      hour: 0,
+      minute: 0,
+    });
+  });
+
+  test('시작 시간이 2023-07-14 23:59, 마감 시간: undefined 일 때 0일 0시간 0분을 반환한다.', () => {
+    const createdAt = '2023-07-14 23:59';
+    const deadline = undefined;
+
+    const result = calculateDeadlineTime(createdAt, deadline);
+
+    expect(result).toEqual({
+      day: 0,
+      hour: 0,
+      minute: 0,
+    });
+  });
 });
diff --git a/frontend/__test__/getSelectedTimeOption.test.ts b/frontend/__test__/getSelectedTimeOption.test.ts
new file mode 100644
index 000000000..7324c2ebc
--- /dev/null
+++ b/frontend/__test__/getSelectedTimeOption.test.ts
@@ -0,0 +1,99 @@
+import { getSelectedTimeOption } from '@utils/post/getSelectedTimeOption';
+
+describe('getSelectedTimeOption 함수에서 day, hour, minute 객체를 입력받아 "10분" | "30분" | "1시간" | "6시간" | "1일" | "사용자 지정" | null 을 반환한다.', () => {
+  test('10분 객체를 입력했을 때 10분을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 0,
+      minute: 10,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('10분');
+  });
+
+  test('30분 객체를 입력했을 때 30분을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 0,
+      minute: 30,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('30분');
+  });
+
+  test('1시간 객체를 입력했을 때 1시간을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 1,
+      minute: 0,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('1시간');
+  });
+
+  test('6시간 객체를 입력했을 때 6시간을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 6,
+      minute: 0,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('6시간');
+  });
+
+  test('1일 객체를 입력했을 때 1일을 반환한다.', () => {
+    const time = {
+      day: 1,
+      hour: 0,
+      minute: 0,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('1일');
+  });
+
+  test('2일 객체를 입력했을 때 사용자지정을 반환한다.', () => {
+    const time = {
+      day: 2,
+      hour: 0,
+      minute: 0,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('사용자지정');
+  });
+
+  test('3분 객체를 입력했을 때 사용자지정을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 0,
+      minute: 3,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe('사용자지정');
+  });
+
+  test('0일 0시간 0분 객체를 입력했을 때 null을 반환한다.', () => {
+    const time = {
+      day: 0,
+      hour: 0,
+      minute: 0,
+    };
+
+    const result = getSelectedTimeOption(time);
+
+    expect(result).toBe(null);
+  });
+});
diff --git a/frontend/src/components/PostForm/index.tsx b/frontend/src/components/PostForm/index.tsx
index 48dcc858b..e102cd398 100644
--- a/frontend/src/components/PostForm/index.tsx
+++ b/frontend/src/components/PostForm/index.tsx
@@ -24,9 +24,11 @@ import WritingVoteOptionList from '@components/optionList/WritingVoteOptionList'
 import { PATH } from '@constants/path';
 import { CATEGORY_COUNT_LIMIT, POST_CONTENT, POST_TITLE } from '@constants/post';
 
+import { calculateDeadlineTime } from '@utils/post/calculateDeadlineTime';
 import { checkWriter } from '@utils/post/checkWriter';
 import { addTimeToDate, formatTimeWithOption } from '@utils/post/formatTime';
 import { getDeadlineTime } from '@utils/post/getDeadlineTime';
+import { getSelectedTimeOption } from '@utils/post/getSelectedTimeOption';
 import { checkIrreplaceableTime } from '@utils/time';
 
 import CategoryWrapper from './CategoryWrapper';
@@ -56,13 +58,11 @@ export default function PostForm({ data, mutate }: PostFormProps) {
   const writingOptionHook = useWritingOption(voteInfo?.options);
   const contentImageHook = useContentImage(imageUrl);
   const { isToastOpen, openToast, toastMessage } = useToast();
-  const [selectTimeOption, setSelectTimeOption] = useState<DeadlineOption | '사용자지정'>();
+  const [selectTimeOption, setSelectTimeOption] = useState<DeadlineOption | '사용자지정' | null>(
+    getSelectedTimeOption(calculateDeadlineTime(createTime, deadline))
+  );
   const { isOpen, openComponent, closeComponent } = useToggle();
-  const [time, setTime] = useState({
-    day: 0,
-    hour: 0,
-    minute: 0,
-  });
+  const [time, setTime] = useState(calculateDeadlineTime(createTime, deadline));
   const baseTime = createTime ? new Date(createTime) : new Date();
   const closeModal = () => {
     if (data && checkIrreplaceableTime(time, data.createTime)) {
@@ -73,10 +73,10 @@ export default function PostForm({ data, mutate }: PostFormProps) {
         minute: 0,
       };
       setTime(updatedTime);
-      setSelectTimeOption(undefined);
+      setSelectTimeOption(null);
     }
 
-    setSelectTimeOption(Object.values(time).every(time => time === 0) ? undefined : '사용자지정');
+    setSelectTimeOption(Object.values(time).every(time => time === 0) ? null : '사용자지정');
     closeComponent();
   };
 
diff --git a/frontend/src/utils/post/calculateDeadlineTime.ts b/frontend/src/utils/post/calculateDeadlineTime.ts
index 072ecb462..ed82ae35f 100644
--- a/frontend/src/utils/post/calculateDeadlineTime.ts
+++ b/frontend/src/utils/post/calculateDeadlineTime.ts
@@ -1,4 +1,12 @@
-export const calculateDeadlineTime = (createdAt: string, deadLine: string) => {
+export const calculateDeadlineTime = (createdAt?: string, deadLine?: string) => {
+  if (!createdAt || !deadLine) {
+    return {
+      day: 0,
+      hour: 0,
+      minute: 0,
+    };
+  }
+
   const createTimeNumber = new Date(createdAt);
 
   const deadlineTimeNumber = new Date(deadLine);
diff --git a/frontend/src/utils/post/getSelectedTimeOption.ts b/frontend/src/utils/post/getSelectedTimeOption.ts
new file mode 100644
index 000000000..6729b144c
--- /dev/null
+++ b/frontend/src/utils/post/getSelectedTimeOption.ts
@@ -0,0 +1,20 @@
+import { DeadlineOption } from '@components/PostForm/constants';
+
+export const getSelectedTimeOption = ({
+  day,
+  hour,
+  minute,
+}: {
+  day: number;
+  hour: number;
+  minute: number;
+}): DeadlineOption | '사용자지정' | null => {
+  if (day === 0 && hour === 0 && minute === 0) return null;
+  if (day === 0 && hour === 0 && minute === 10) return '10분';
+  if (day === 0 && hour === 0 && minute === 30) return '30분';
+  if (day === 0 && hour === 1 && minute === 0) return '1시간';
+  if (day === 0 && hour === 6 && minute === 0) return '6시간';
+  if (day === 1 && hour === 0 && minute === 0) return '1일';
+
+  return '사용자지정';
+};