diff --git a/src/main/kotlin/kr/co/vividnext/sodalive/v2/api/home/dto/HomeRecommendationResponse.kt b/src/main/kotlin/kr/co/vividnext/sodalive/v2/api/home/dto/HomeRecommendationResponse.kt
index e6a57799..bf1a6039 100644
--- a/src/main/kotlin/kr/co/vividnext/sodalive/v2/api/home/dto/HomeRecommendationResponse.kt
+++ b/src/main/kotlin/kr/co/vividnext/sodalive/v2/api/home/dto/HomeRecommendationResponse.kt
@@ -1,15 +1,10 @@
 package kr.co.vividnext.sodalive.v2.api.home.dto
 
 import java.time.LocalDateTime
-import java.time.ZoneId
 import java.time.ZoneOffset
-import java.time.format.DateTimeFormatter
-
-private val KST_ZONE: ZoneId = ZoneId.of("Asia/Seoul")
 
 internal fun LocalDateTime.toUtcIso(): String {
-    val instant = this.atZone(KST_ZONE).withZoneSameInstant(ZoneOffset.UTC).toInstant()
-    return DateTimeFormatter.ISO_INSTANT.format(instant)
+    return this.atOffset(ZoneOffset.UTC).toInstant().toString()
 }
 
 internal fun imageUrl(cloudFrontHost: String, path: String?): String? {
diff --git a/src/main/kotlin/kr/co/vividnext/sodalive/v2/chat/service/ChatRoomListService.kt b/src/main/kotlin/kr/co/vividnext/sodalive/v2/chat/service/ChatRoomListService.kt
index 20bd7986..888775ea 100644
--- a/src/main/kotlin/kr/co/vividnext/sodalive/v2/chat/service/ChatRoomListService.kt
+++ b/src/main/kotlin/kr/co/vividnext/sodalive/v2/chat/service/ChatRoomListService.kt
@@ -4,6 +4,7 @@ import kr.co.vividnext.sodalive.chat.room.ChatMessageType
 import kr.co.vividnext.sodalive.chat.room.repository.ChatRoomRepository
 import kr.co.vividnext.sodalive.common.SodaException
 import kr.co.vividnext.sodalive.member.Member
+import kr.co.vividnext.sodalive.v2.api.home.dto.toUtcIso
 import kr.co.vividnext.sodalive.v2.chat.dto.ChatRoomListItemResponse
 import kr.co.vividnext.sodalive.v2.chat.dto.ChatRoomListPageResponse
 import kr.co.vividnext.sodalive.v2.chat.dto.ChatRoomListQueryDto
@@ -14,7 +15,6 @@ import org.springframework.data.domain.PageRequest
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
 import java.time.LocalDateTime
-import java.time.ZoneOffset
 
 @Service
 @Transactional(readOnly = true)
@@ -90,7 +90,7 @@ class ChatRoomListService(
             targetName = targetName,
             targetImageUrl = imageUrl(targetImagePath),
             lastMessage = previewMessage(),
-            lastMessageAt = lastMessageAt.toUtcIsoString()
+            lastMessageAt = lastMessageAt.toUtcIso()
         )
     }
 
@@ -118,10 +118,6 @@ class ChatRoomListService(
         return ChatRoomListCursor(lastMessageAt, chatType, roomId)
     }
 
-    private fun LocalDateTime.toUtcIsoString(): String {
-        return atOffset(ZoneOffset.UTC).toInstant().toString()
-    }
-
     private fun ChatRoomListQueryDto.isAfter(cursor: ChatRoomListCursor): Boolean {
         if (lastMessageAt.isBefore(cursor.lastMessageAt)) return true
         if (lastMessageAt.isAfter(cursor.lastMessageAt)) return false