diff --git a/src/main/ai/AiWorker.ts b/src/main/ai/AiWorker.ts
index 7eef0a8..fe1df6e 100644
--- a/src/main/ai/AiWorker.ts
+++ b/src/main/ai/AiWorker.ts
@@ -118,7 +118,7 @@ export class AiWorker {
   private async processJob(job: Job): Promise<void> {
     const max = this.backoffsMs.length;
     for (let attempt = job.attempts; attempt < max; attempt++) {
-      const startMs = Date.now();
+      const startMs = this.now().getTime();
       try {
         const note = this.repo.findById(job.noteId);
         if (!note || note.aiStatus !== 'pending') return;
@@ -150,8 +150,8 @@ export class AiWorker {
             kind: 'ai_succeeded',
             payload: {
               noteId: job.noteId,
-              durationMs: Date.now() - startMs,
-              attempts: attempt
+              durationMs: this.now().getTime() - startMs,
+              attempts: attempt + 1
             }
           }).catch(() => {});
         }
diff --git a/src/main/services/TelemetryService.ts b/src/main/services/TelemetryService.ts
index 2df5b45..9b2778a 100644
--- a/src/main/services/TelemetryService.ts
+++ b/src/main/services/TelemetryService.ts
@@ -55,9 +55,12 @@ export class TelemetryService {
   }
 
   async emit(input: EmitInput): Promise<void> {
-    const ts = this.now().toISOString();
+    // 회차 1 review (PR #13) — `now()` 한 번만 호출. KST 자정 경계에서 ts 와 파일명 일자가
+    // 어긋나는 것을 방지.
+    const nowDate = this.now();
+    const ts = nowDate.toISOString();
     const event = validateEvent({ ts, kind: input.kind, payload: input.payload });
-    const filePath = join(this.dir, `events-${todayKstIso(this.now())}.jsonl`);
+    const filePath = join(this.dir, `events-${todayKstIso(nowDate)}.jsonl`);
     try {
       await mkdir(this.dir, { recursive: true });
       await appendFile(filePath, JSON.stringify(event) + '\n', 'utf8');
@@ -77,9 +80,14 @@ export class TelemetryService {
     }
     const cutoffMs = this.now().getTime() - this.retentionDays * 24 * 60 * 60 * 1000;
     const cutoffIso = todayKstIso(new Date(cutoffMs));
+    // 회차 1 review (PR #13) — 매직 슬라이스 `n.slice(7, 17)` 대신 정규식 capture 그룹으로
+    // 일자를 추출. prefix 변경 시 정규식 한 곳만 고치면 됨.
+    const datePattern = /^events-(\d{4}-\d{2}-\d{2})\.jsonl$/;
     const fileNames = entries
-      .filter((n) => /^events-\d{4}-\d{2}-\d{2}\.jsonl$/.test(n))
-      .filter((n) => n.slice(7, 17) >= cutoffIso)
+      .filter((n) => {
+        const m = datePattern.exec(n);
+        return m !== null && m[1]! >= cutoffIso;
+      })
       .sort();
     for (const name of fileNames) {
       let raw: string;
diff --git a/tests/unit/AiWorker.test.ts b/tests/unit/AiWorker.test.ts
index ed490be..7e3803f 100644
--- a/tests/unit/AiWorker.test.ts
+++ b/tests/unit/AiWorker.test.ts
@@ -222,7 +222,9 @@ describe('AiWorker telemetry emit', () => {
     const succeeded = events.find((e) => e.kind === 'ai_succeeded');
     expect(succeeded).toBeDefined();
     expect(succeeded!.payload.noteId).toBe(id);
-    expect(succeeded!.payload.attempts).toBe(0);
+    // attempts = 시도한 횟수 (count, 1-based). 첫 시도 성공이므로 1.
+    // 회차 1 review (PR #13) 의 비대칭 의미 통일 결과 — 실패 경로의 `attempt + 1` 과 동일 의미.
+    expect(succeeded!.payload.attempts).toBe(1);
     expect(succeeded!.payload.durationMs).toBeGreaterThanOrEqual(0);
   });