diff --git a/src/components/SyncSettings.tsx b/src/components/SyncSettings.tsx
index 3f60a27..06a06f5 100644
--- a/src/components/SyncSettings.tsx
+++ b/src/components/SyncSettings.tsx
@@ -3,7 +3,7 @@ import React, { useState, useEffect } from 'react';
 import { Switch } from "@/components/ui/switch";
 import { Label } from "@/components/ui/label";
 import { CloudUpload, RefreshCw, AlertCircle } from "lucide-react";
-import { isSyncEnabled, setSyncEnabled, syncAllData, getLastSyncTime, trySyncAllData } from "@/utils/syncUtils";
+import { isSyncEnabled, setSyncEnabled, syncAllData, getLastSyncTime, trySyncAllData, SyncResult } from "@/utils/syncUtils";
 import { toast } from "@/hooks/useToast.wrapper";
 import { useAuth } from "@/contexts/auth";
 import { useNavigate } from "react-router-dom";
@@ -59,7 +59,7 @@ const SyncSettings = () => {
             toast({
               title: "동기화 일부 완료",
               description: "일부 데이터만 동기화되었습니다. 다시 시도해보세요.",
-              variant: "warning"
+              variant: "destructive"
             });
           } else {
             toast({
@@ -115,13 +115,13 @@ const SyncSettings = () => {
           toast({
             title: "다운로드만 성공",
             description: "서버 데이터를 가져왔지만, 업로드에 실패했습니다.",
-            variant: "warning"
+            variant: "destructive"
           });
         } else if (result.uploadSuccess) {
           toast({
             title: "업로드만 성공",
             description: "로컬 데이터를 업로드했지만, 다운로드에 실패했습니다.",
-            variant: "warning"
+            variant: "destructive"
           });
         }
         setLastSync(getLastSyncTime());
diff --git a/src/utils/sync/time.ts b/src/utils/sync/time.ts
index 96e9ba8..188763d 100644
--- a/src/utils/sync/time.ts
+++ b/src/utils/sync/time.ts
@@ -13,11 +13,12 @@ export const getLastSyncTime = (): string | null => {
 
 /**
  * 마지막 동기화 시간 설정
+ * @param customValue 설정할 특정 값 (옵션)
  */
-export const setLastSyncTime = (): void => {
+export const setLastSyncTime = (customValue?: string): void => {
   try {
-    const now = new Date().toISOString();
-    localStorage.setItem('lastSyncTime', now);
+    const value = customValue || new Date().toISOString();
+    localStorage.setItem('lastSyncTime', value);
   } catch (error) {
     console.error('마지막 동기화 시간 업데이트 중 오류:', error);
   }
diff --git a/src/utils/syncUtils.ts b/src/utils/syncUtils.ts
index cc2399f..6a8b1f7 100644
--- a/src/utils/syncUtils.ts
+++ b/src/utils/syncUtils.ts
@@ -49,8 +49,18 @@ export const syncAllData = async (userId: string): Promise<void> => {
   }
 };
 
+// trySyncAllData의 반환 타입 명시적 정의
+// 동기화 결과를 위한 인터페이스 정의
+export interface SyncResult {
+  success: boolean;
+  partial?: boolean;
+  downloadSuccess?: boolean;
+  uploadSuccess?: boolean;
+  error?: any;
+}
+
 // 안전하게 동기화 시도하는 함수 개선
-export const trySyncAllData = async (userId: string): Promise<{ success: boolean, error?: any }> => {
+export const trySyncAllData = async (userId: string): Promise<SyncResult> => {
   if (!userId || !isSyncEnabled()) return { success: true };
   
   let downloadSuccess = false;
@@ -93,7 +103,7 @@ export const trySyncAllData = async (userId: string): Promise<{ success: boolean
     }
     
     // 하나라도 성공했으면 부분 성공으로 간주
-    const result = { 
+    const result: SyncResult = { 
       success: downloadSuccess || uploadSuccess,
       partial: (downloadSuccess && !uploadSuccess) || (!downloadSuccess && uploadSuccess),
       downloadSuccess,