diff --git a/schema.gql b/schema.gql
index e73b5b63..4e2c074c 100644
--- a/schema.gql
+++ b/schema.gql
@@ -603,7 +603,7 @@ input CreatePostInput {
   summary: String!
   content: String!
   tags: [String!]!
-  lastModifiedDate: String!
+  lastModifiedDate: DateTime!
   isPublic: Boolean
 }
 
diff --git a/src/posts/dtos/create-post.input.ts b/src/posts/dtos/create-post.input.ts
index 8edf6f62..3a9d11b1 100644
--- a/src/posts/dtos/create-post.input.ts
+++ b/src/posts/dtos/create-post.input.ts
@@ -1,4 +1,4 @@
-import { InputType, Field } from '@nestjs/graphql'
+import { InputType, Field, } from '@nestjs/graphql'
 import {
   IsString,
   IsNotEmpty,
@@ -45,9 +45,9 @@ export class CreatePostInput {
   public readonly tags: string[]
 
   @Field({ nullable: false })
-  @IsString()
+  @IsDate()
   @IsNotEmpty()
-  public readonly lastModifiedDate: string
+  public readonly lastModifiedDate: Date
 
   @Field({ nullable: true })
   public readonly isPublic?: boolean
diff --git a/src/posts/posts.resolver.ts b/src/posts/posts.resolver.ts
index 7c50a479..86410301 100644
--- a/src/posts/posts.resolver.ts
+++ b/src/posts/posts.resolver.ts
@@ -23,7 +23,7 @@ export class PostsResolver {
   }
 
   @Query(() => PostModel)
-  // @UseGuards(GqlAuthGuard)
+  @UseGuards(GqlAuthGuard)
   public async getPosts(@Args('input') input: PaginationInput) {
     return this.postsService.findByPagination(input)
   }
@@ -34,19 +34,19 @@ export class PostsResolver {
   }
 
   @Mutation(() => PostItemModel)
-  // @UseGuards(GqlAuthGuard)
+  @UseGuards(GqlAuthGuard)
   public async createPost(@Args('input') input: CreatePostInput) {
     return this.postsService.create(input)
   }
 
   @Mutation(() => PostItemModel)
-  // @UseGuards(GqlAuthGuard)
+  @UseGuards(GqlAuthGuard)
   public async updatePostById(@Args('input') input: UpdatePostInput) {
     return this.postsService.update(input)
   }
 
   @Mutation(() => PostItemModel)
-  // @UseGuards(GqlAuthGuard)
+  @UseGuards(GqlAuthGuard)
   public async deletePostById(@Args({ name: 'id', type: () => ID }) id: string) {
     return this.postsService.deleteOneById(id)
   }