diff --git a/gateway/src/main/java/com/oing/controller/CalendarController.java b/gateway/src/main/java/com/oing/controller/CalendarController.java
index 134a0799..22552623 100644
--- a/gateway/src/main/java/com/oing/controller/CalendarController.java
+++ b/gateway/src/main/java/com/oing/controller/CalendarController.java
@@ -91,24 +91,35 @@ public BannerResponse getBanner(String yearMonth, String familyId) {
         int allFamilyMembersUploadedStreaks = 0;
         boolean allFamilyMembersUploadedStreaked = true;
 
-        // 한 달 동안 '가족이 전부 올린 날'과 '가족이 전부 올린 날의 연속'을 계산하기 위해, 1일부터 마지막 날까지 순회한다.
+        // 한 달 동안 '가족이 전부 업로드한 날'과 '전부 업로드한 날의 연속'을 계산하기 위해, 1일부터 마지막 날까지 순회한다.
         while (startDate.isBefore(endDate)) {
-            List<String> familyMembersIds = memberService.findFamilyMembersIdsByFamilyJoinAtBefore(familyId, startDate.plusDays(1));
             boolean allFamilyMembersUploaded = true;
-            for (String memberId : familyMembersIds) {
-                if (!memberPostService.existsByMemberIdAndFamilyIdAndCreatedAt(memberId, familyId, startDate)) {
-                    allFamilyMembersUploaded = false;
-                    break;
+
+            if (memberPostService.existsByFamilyIdAndCreatedAt(familyId, startDate)) {
+                List<String> familyMembersIds = memberService.findFamilyMembersIdsByFamilyJoinAtBefore(familyId, startDate.plusDays(1));
+                for (String memberId : familyMembersIds) {
+                    if (!memberPostService.existsByMemberIdAndFamilyIdAndCreatedAt(memberId, familyId, startDate)) {
+                        allFamilyMembersUploaded = false;
+                        break;
+                    }
                 }
+
+            } else {
+                // 게시글이 없다면, 계산에서 제외
+                // 해당 날짜에 가족과 게시물이 없는 경우, allFamilyMembersUploaded = true 가 되는 것을 방지
+                // edge case: 게시물을 하나라도 없로드 하고 글을 업로드하지 않은 회원이 탈퇴하면, allFamilyMembersUploaded이 true로 변함 -> 핸들링할 수 없는 케이스
+                allFamilyMembersUploaded = false;
             }
 
+
+            // (가족 전부 업로드한 날의 수, 연속해서 업로드한 여부, 연속해서 업로드한 날의 수) 계산
             if (allFamilyMembersUploaded) {
                 allFamilyMembersUploadedDays++;
 
                 if (allFamilyMembersUploadedStreaked)
-                    allFamilyMembersUploadedStreaks++; // 가족 전체 업로드가 연속되면, Streak + 1
+                    allFamilyMembersUploadedStreaks++;
             } else {
-                allFamilyMembersUploadedStreaked = false;  // 가족 전체 업로드가 연속되지 못하면, Streak false
+                allFamilyMembersUploadedStreaked = false;
             }
 
             startDate = startDate.plusDays(1);
diff --git a/gateway/src/main/java/com/oing/repository/MemberPostRepositoryCustomImpl.java b/gateway/src/main/java/com/oing/repository/MemberPostRepositoryCustomImpl.java
index 53714e90..b45d7f98 100644
--- a/gateway/src/main/java/com/oing/repository/MemberPostRepositoryCustomImpl.java
+++ b/gateway/src/main/java/com/oing/repository/MemberPostRepositoryCustomImpl.java
@@ -5,6 +5,7 @@
 import com.querydsl.core.types.Ops;
 import com.querydsl.core.types.Projections;
 import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.core.types.dsl.DateTimePath;
 import com.querydsl.core.types.dsl.Expressions;
 import com.querydsl.jpa.JPAExpressions;
 import com.querydsl.core.types.dsl.DateTimeTemplate;
@@ -86,16 +87,31 @@ private BooleanExpression eqMemberId(String memberId) {
     }
 
     @Override
-    public boolean existsByMemberIdAndFamilyIdAndCreatedAt(String memberId, String familyId, LocalDate postDate) {
-        DateTimeTemplate<LocalDate> createdAtDate = Expressions.dateTimeTemplate(LocalDate.class,
-                "DATE({0})", memberPost.createdAt);
+    public boolean existsByFamilyIdAndCreatedAt(String familyId, LocalDate postDate) {
+        return queryFactory
+                .select(memberPost.id)
+                .from(memberPost)
+                .where(
+                        memberPost.familyId.eq(familyId),
+                        dateExpr(memberPost.createdAt).eq(postDate)
+                )
+                .fetchFirst() != null;
+    }
 
+    @Override
+    public boolean existsByMemberIdAndFamilyIdAndCreatedAt(String memberId, String familyId, LocalDate postDate) {
         return queryFactory
                 .select(memberPost.id)
                 .from(memberPost)
-                .where(memberPost.memberId.eq(memberId)
-                        .and(memberPost.familyId.eq(familyId))
-                        .and(createdAtDate.eq(postDate)))
+                .where(
+                        memberPost.memberId.eq(memberId),
+                        memberPost.familyId.eq(familyId),
+                        dateExpr(memberPost.createdAt).eq(postDate)
+                )
                 .fetchFirst() != null;
     }
+
+    private DateTimeTemplate<LocalDate> dateExpr(DateTimePath<LocalDateTime> localDateTime) {
+        return Expressions.dateTimeTemplate(LocalDate.class, "DATE({0})", localDateTime);
+    }
 }
diff --git a/post/src/main/java/com/oing/repository/MemberPostRepositoryCustom.java b/post/src/main/java/com/oing/repository/MemberPostRepositoryCustom.java
index 20f6c39b..1ba6f6fd 100644
--- a/post/src/main/java/com/oing/repository/MemberPostRepositoryCustom.java
+++ b/post/src/main/java/com/oing/repository/MemberPostRepositoryCustom.java
@@ -16,5 +16,8 @@ public interface MemberPostRepositoryCustom {
 
     long countMonthlyPostByFamilyId(int year, int month, String familyId);
 
+    boolean existsByFamilyIdAndCreatedAt(String familyId, LocalDate postDate);
+
     boolean existsByMemberIdAndFamilyIdAndCreatedAt(String memberId, String familyId, LocalDate postDate);
+
 }
diff --git a/post/src/main/java/com/oing/service/MemberPostService.java b/post/src/main/java/com/oing/service/MemberPostService.java
index 441bdb5b..6f7cc773 100644
--- a/post/src/main/java/com/oing/service/MemberPostService.java
+++ b/post/src/main/java/com/oing/service/MemberPostService.java
@@ -94,6 +94,10 @@ public List<String> getMemberIdsPostedToday(LocalDate date) {
         return memberPostRepository.getMemberIdsPostedToday(date);
     }
 
+    public boolean existsByFamilyIdAndCreatedAt(String familyId, LocalDate postDate) {
+        return memberPostRepository.existsByFamilyIdAndCreatedAt(familyId, postDate);
+    }
+
     public boolean existsByMemberIdAndFamilyIdAndCreatedAt(String memberId, String familyId, LocalDate postDate) {
         return memberPostRepository.existsByMemberIdAndFamilyIdAndCreatedAt(memberId, familyId, postDate);
     }