fix: 스터디 시간 없을 경우 예외처리

apps/admin/app/studies/[studyId]/_components/header/Header.tsx

@@ -56,19 +56,29 @@ const Header = ({
       mentorName,
       studyType,
       dayOfWeek,
-      startTime: { hour: startHour, minute: startMinute },
-      endTime: { hour: endHour, minute: endMinute },
+      startTime,
+      endTime,
       totalWeek,
       period: { startDate, endDate },
       introduction,
       notionLink,
     } = studyInfo;
 
+    const studySchedule = () => {
+      if (startTime && endDate) {
+        const { hour: startHour, minute: startMinute } = startTime;
+        const { hour: endHour, minute: endMinute } = endTime;
+        return `${dayToKorean[dayOfWeek]} ${startHour}:${padWithZero(startMinute)}-
+        ${endHour}:${padWithZero(endMinute)}`;
+      } else {
+        null;
+      }
+    };
+
     const { month: startMonth, day: startDay } = parseISODate(startDate);
     const { month: endMonth, day: endDay } = parseISODate(endDate);
     const studySemester = `${academicYear}-${semester === "FIRST" ? 1 : 2}`;
-    const studySchedule = `${dayToKorean[dayOfWeek]} ${startHour}:${padWithZero(startMinute)}-
-  ${endHour}:${padWithZero(endMinute)}`;
+
     const studyPeriod = `${padWithZero(startMonth)}.${padWithZero(startDay)}-
   ${padWithZero(endMonth)}.${padWithZero(endDay)}`;
 
@@ -124,10 +134,14 @@ const Header = ({
                   스터디 일정
                 </Text>
                 <Flex gap="xs">
-                  <Text as="h5" color="sub">
-                    {studySchedule}
-                  </Text>
-                  <ItemSeparator />
+                  {startTime && (
+                    <Flex gap="xs">
+                      <Text as="h5" color="sub">
+                        {studySchedule()}
+                      </Text>
+                      <ItemSeparator />
+                    </Flex>
+                  )}
                   <Text as="h5" color="sub">
                     {totalWeek}주 코스
                   </Text>