[REFACTOR] UTC 기준 시간 통일

src/main/java/com/mr/Application.java

@@ -1,17 +1,25 @@
 package com.mr;
 
+import jakarta.annotation.PostConstruct;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
 import org.springframework.retry.annotation.EnableRetry;
 import org.springframework.scheduling.annotation.EnableScheduling;
 
+import java.util.TimeZone;
+
 @EnableRetry
 @EnableScheduling
 @EnableJpaAuditing
 @SpringBootApplication
 public class Application {
 
+    @PostConstruct
+    public void init() {
+        TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
+    }
+
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }

src/main/java/com/mr/domain/analysis/dto/res/AnalysisCreateResponseDTO.java

@@ -1,16 +1,21 @@
 package com.mr.domain.analysis.dto.res;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.mr.domain.analysis.entity.Analysis;
 import com.mr.domain.analysis.entity.enums.AnalysisStatus;
-import java.time.LocalDateTime;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.time.Instant;
 
 public record AnalysisCreateResponseDTO(
         Long analysisId,
         Long playingId,
         AnalysisStatus status,
         Integer startBar,
         Integer endBar,
-        LocalDateTime createdAt
+        @Schema(description = "분석 생성 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant createdAt
 ) {
     public static AnalysisCreateResponseDTO from(Analysis analysis) {
         return new AnalysisCreateResponseDTO(analysis.getId(), analysis.getPlaying().getId(), analysis.getStatus(),

src/main/java/com/mr/domain/analysis/dto/res/AnalysisResultResponseDTO.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.mr.domain.analysis.entity.enums.AnalysisStatus;
 import com.mr.domain.backingtrack.entity.BackingTrack;
 import com.mr.domain.playing.entity.Playing;
@@ -11,8 +12,10 @@
 import com.mr.domain.analysis.entity.enums.ContentFormat;
 import com.mr.domain.analysis.entity.enums.LlmStatus;
 import com.mr.domain.analysis.entity.enums.ReportGenerationType;
+import io.swagger.v3.oas.annotations.media.Schema;
+
 import java.math.BigDecimal;
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.Locale;
 
 public record AnalysisResultResponseDTO(
@@ -22,7 +25,11 @@ public record AnalysisResultResponseDTO(
         String genre,
         String key,
         Integer bpm,
-        LocalDateTime playedAt,
+
+        @Schema(description = "연주 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant playedAt,
+
         String recordingFileUrl,
         String backingTrackAudioFileUrl,
         AnalysisStatus status,
@@ -34,8 +41,14 @@ public record AnalysisResultResponseDTO(
         DomainScores domainScores,
         Report report,
         @JsonProperty("result") JsonNode rawResult,
-        LocalDateTime createdAt,
-        LocalDateTime completedAt
+
+        @Schema(description = "생성 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant createdAt,
+
+        @Schema(description = "완료 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant completedAt
 ) {
 
     public static AnalysisResultResponseDTO from(
@@ -107,8 +120,14 @@ public record Report(
             String content,
             String modelName,
             String promptVersion,
-            LocalDateTime createdAt,
-            LocalDateTime updatedAt
+
+            @Schema(description = "리포트 생성 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+            @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+            Instant createdAt,
+
+            @Schema(description = "리포트 수정 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+            @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+            Instant updatedAt
     ) {
 
         private static Report fromNullable(AnalysisReport analysisReport) {
@@ -129,4 +148,4 @@ private static Report fromNullable(AnalysisReport analysisReport) {
             );
         }
     }
-}
+}

src/main/java/com/mr/domain/analysis/dto/res/AnalysisStatusResponseDTO.java

@@ -1,16 +1,25 @@
 package com.mr.domain.analysis.dto.res;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.mr.domain.analysis.entity.Analysis;
 import com.mr.domain.analysis.entity.enums.AnalysisStatus;
-import java.time.LocalDateTime;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.time.Instant;
 
 public record AnalysisStatusResponseDTO(
         Long analysisId,
         AnalysisStatus status,
         Integer progressRate,
         String message,
-        LocalDateTime createdAt,
-        LocalDateTime completedAt
+
+        @Schema(description = "생성 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant createdAt,
+
+        @Schema(description = "완료 일시 (KST 기준 응답)", example = "2026-08-11T18:00:00", type = "string")
+        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss", timezone = "Asia/Seoul")
+        Instant completedAt
 ) {
 
     public static AnalysisStatusResponseDTO from(

src/main/java/com/mr/domain/analysis/entity/Analysis.java

@@ -10,7 +10,7 @@
 import jakarta.persistence.*;
 
 import java.math.BigDecimal;
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.Objects;
 import lombok.AccessLevel;
@@ -92,17 +92,17 @@ public class Analysis extends BaseCreatedEntity {
     private String failedReason;
 
     @Column(name = "processing_started_at")
-    private LocalDateTime processingStartedAt;
+    private Instant processingStartedAt;
 
     @Column(name = "completed_at")
-    private LocalDateTime completedAt;
+    private Instant completedAt;
 
     @Builder(access = AccessLevel.PRIVATE)
     private Analysis(User user, Playing playing, String analysisVersion, Integer startBar, Integer endBar,
                      AnalysisStatus status, Integer totalScore, AnalysisGrade grade, String summary,
                      String analysisRequestJson, BigDecimal scaleScore, BigDecimal tensionScore,
                      BigDecimal progressionScore, BigDecimal voiceLeadingScore, String rawResultJson,
-                     String failedReason, LocalDateTime completedAt) {
+                     String failedReason, Instant completedAt) {
         validateUser(user);
         validatePlaying(playing);
         validateOwnerConsistency(user, playing);
@@ -172,7 +172,7 @@ private static void validateBarRange(Integer startBar, Integer endBar) {
         }
     }
 
-    public LocalDateTime startProcessing(LocalDateTime now) {
+    public Instant startProcessing(Instant now) {
         if (this.status != AnalysisStatus.PENDING) {
             throw new IllegalStateException("PENDING 상태의 분석만 PROCESSING으로 변경할 수 있습니다.");
         }
@@ -181,21 +181,21 @@ public LocalDateTime startProcessing(LocalDateTime now) {
         return this.processingStartedAt;
     }
 
-    public LocalDateTime restartProcessing(LocalDateTime now) {
+    public Instant restartProcessing(Instant now) {
         if (this.status != AnalysisStatus.PROCESSING) {
             throw new IllegalStateException("PROCESSING 상태의 분석만 다시 시작할 수 있습니다.");
         }
         this.processingStartedAt = nextProcessingStartedAt(now);
         return this.processingStartedAt;
     }
 
-    public boolean isCurrentProcessing(LocalDateTime expectedProcessingStartedAt) {
+    public boolean isCurrentProcessing(Instant expectedProcessingStartedAt) {
         return this.status == AnalysisStatus.PROCESSING
                 && Objects.equals(this.processingStartedAt, expectedProcessingStartedAt);
     }
 
-    private LocalDateTime nextProcessingStartedAt(LocalDateTime requestedAt) {
-        LocalDateTime next = Objects.requireNonNull(requestedAt).truncatedTo(ChronoUnit.MILLIS);
+    private Instant nextProcessingStartedAt(Instant requestedAt) {
+        Instant next = Objects.requireNonNull(requestedAt).truncatedTo(ChronoUnit.MILLIS);
         if (this.processingStartedAt != null && !next.isAfter(this.processingStartedAt)) {
             return this.processingStartedAt.plus(1, ChronoUnit.MILLIS);
         }
@@ -204,7 +204,7 @@ private LocalDateTime nextProcessingStartedAt(LocalDateTime requestedAt) {
 
     public void complete(Integer totalScore, AnalysisGrade grade, String summary, BigDecimal scaleScore,
                          BigDecimal tensionScore, BigDecimal progressionScore, BigDecimal voiceLeadingScore,
-                         String rawResultJson, LocalDateTime completedAt) {
+                         String rawResultJson, Instant completedAt) {
         if (this.status != AnalysisStatus.PROCESSING) {
             throw new IllegalStateException("PROCESSING 상태의 분석만 완료 처리할 수 있습니다.");
         }
@@ -220,7 +220,7 @@ public void complete(Integer totalScore, AnalysisGrade grade, String summary, Bi
         this.completedAt = Objects.requireNonNull(completedAt);
     }
 
-    public void fail(String failedReason, LocalDateTime completedAt) {
+    public void fail(String failedReason, Instant completedAt) {
         if (this.status == AnalysisStatus.COMPLETED || this.status == AnalysisStatus.FAILED) {
             throw new IllegalStateException("이미 완료된 분석은 실패 처리할 수 없습니다.");
         }

src/main/java/com/mr/domain/analysis/model/AnalysisProcessingClaim.java

@@ -1,9 +1,9 @@
 package com.mr.domain.analysis.model;
 
-import java.time.LocalDateTime;
+import java.time.Instant;
 
 public record AnalysisProcessingClaim(
         String requestJson,
-        LocalDateTime processingStartedAt
+        Instant processingStartedAt
 ) {
 }

src/main/java/com/mr/domain/analysis/repository/AnalysisRepository.java

@@ -3,7 +3,8 @@
 import com.mr.domain.analysis.entity.Analysis;
 import com.mr.domain.analysis.entity.enums.AnalysisStatus;
 import jakarta.persistence.LockModeType;
-import java.time.LocalDateTime;
+
+import java.time.Instant;
 import java.util.List;
 import java.util.Optional;
 import org.springframework.data.domain.Pageable;
@@ -28,7 +29,7 @@ public interface AnalysisRepository extends JpaRepository<Analysis, Long> {
             """)
     List<Long> findIdsByStatusAndCreatedAtBefore(
             @Param("status") AnalysisStatus status,
-            @Param("cutoff") LocalDateTime cutoff,
+            @Param("cutoff") Instant cutoff,
             Pageable pageable
     );
 
@@ -39,7 +40,7 @@ List<Long> findIdsByStatusAndCreatedAtBefore(
             """)
     List<Long> findIdsByStatusAndProcessingStartedAtBefore(
             @Param("status") AnalysisStatus status,
-            @Param("cutoff") LocalDateTime cutoff,
+            @Param("cutoff") Instant cutoff,
             Pageable pageable
     );
 
@@ -72,7 +73,7 @@ List<Analysis> findByPlayingIdAndUserIdOrderByStartBarAscIdAsc(
     List<Analysis> findByUserAndStatusSince(
             @Param("userId") Long userId,
             @Param("status") AnalysisStatus status,
-            @Param("since") LocalDateTime since
+            @Param("since") Instant since
     );
 
     @Query("""

src/main/java/com/mr/domain/analysis/scheduler/AnalysisRecoveryScheduler.java

@@ -4,7 +4,7 @@
 import com.mr.domain.analysis.repository.AnalysisRepository;
 import java.time.Clock;
 import java.time.Duration;
-import java.time.LocalDateTime;
+import java.time.Instant;
 import java.util.List;
 
 import com.mr.domain.analysis.service.AnalysisProcessingService;
@@ -51,15 +51,15 @@ public AnalysisRecoveryScheduler(
             fixedDelayString = "${analysis.recovery.fixed-delay-ms:30000}"
     )
     public void recoverPendingAnalyses() {
-        LocalDateTime now = LocalDateTime.now(clock);
+        Instant now = Instant.now(clock);
         List<Long> pendingIds = analysisRepository.findIdsByStatusAndCreatedAtBefore(
                 AnalysisStatus.PENDING,
                 now.minus(pendingThreshold),
                 PageRequest.of(0, batchSize)
         );
         submitPending(pendingIds);
 
-        LocalDateTime processingCutoff = now.minus(processingThreshold);
+        Instant processingCutoff = now.minus(processingThreshold);
         List<Long> processingIds = analysisRepository.findIdsByStatusAndProcessingStartedAtBefore(
                 AnalysisStatus.PROCESSING,
                 processingCutoff,
@@ -79,7 +79,7 @@ private void submitPending(List<Long> analysisIds) {
         }
     }
 
-    private void submitStaleProcessing(List<Long> analysisIds, LocalDateTime cutoff) {
+    private void submitStaleProcessing(List<Long> analysisIds, Instant cutoff) {
         for (Long analysisId : analysisIds) {
             try {
                 taskExecutor.execute(() -> analysisProcessingService.recoverStaleProcessing(analysisId, cutoff));

src/main/java/com/mr/domain/analysis/service/AnalysisProcessingService.java

@@ -7,7 +7,8 @@
 import com.mr.domain.analysis.model.GeneratedAnalysisReport;
 import com.mr.global.client.ai.AiAnalysisRequest;
 import com.mr.global.client.ai.AiServerClient;
-import java.time.LocalDateTime;
+
+import java.time.Instant;
 import java.util.Optional;
 import java.util.function.Supplier;
 import lombok.RequiredArgsConstructor;
@@ -29,7 +30,7 @@ public void process(Long analysisId) {
         processClaimed(analysisId, () -> analysisStateService.startProcessing(analysisId));
     }
 
-    public void recoverStaleProcessing(Long analysisId, LocalDateTime cutoff) {
+    public void recoverStaleProcessing(Long analysisId, Instant cutoff) {
         processClaimed(analysisId, () -> analysisStateService.restartStaleProcessing(analysisId, cutoff));
     }