diff --git a/backend/app/controllers/posts_controller.rb b/backend/app/controllers/posts_controller.rb
index 33fef9a..b7659a5 100644
--- a/backend/app/controllers/posts_controller.rb
+++ b/backend/app/controllers/posts_controller.rb
@@ -2,41 +2,83 @@ class PostsController < ApplicationController
   Event = Struct.new(:post, :tag, :user, :change_type, :timestamp, keyword_init: true)
 
   def index
+    url = params[:url].presence
+    title = params[:title].presence
+    original_created_from = params[:original_created_from].presence
+    original_created_to = params[:original_created_to].presence
+    created_between = params[:created_from].presence, params[:created_to].presence
+    updated_between = params[:updated_from].presence, params[:updated_to].presence
+
+    order = params[:order].to_s.split(':', 2).map(&:strip)
+    unless order[0].in?(['title', 'url', 'original_created_at', 'created_at', 'updated_at'])
+      order[0] = 'original_created_at'
+    end
+    unless order[1].in?(['asc', 'desc'])
+      order[1] =
+          if order[0].in?(['title', 'url'])
+            'asc'
+          else
+            'desc'
+          end
+    end
+
     page = (params[:page].presence || 1).to_i
     limit = (params[:limit].presence || 20).to_i
-    cursor = params[:cursor].presence
 
     page = 1 if page < 1
     limit = 1 if limit < 1
 
     offset = (page - 1) * limit
 
-    sort_sql =
-        'COALESCE(posts.original_created_before - INTERVAL 1 SECOND,' +
-        'posts.original_created_from,' +
-        'posts.created_at)'
+    pt_max_sql =
+        PostTag
+        .select('post_id, MAX(updated_at) AS max_updated_at')
+        .group('post_id')
+        .to_sql
+
+    updated_at_all_sql =
+        'GREATEST(posts.updated_at,' +
+        'COALESCE(pt_max.max_updated_at, posts.updated_at))'
+
     q =
         filtered_posts
+        .joins("LEFT JOIN (#{ pt_max_sql }) pt_max ON pt_max.post_id = posts.id")
+        .reselect('posts.*', Arel.sql("#{ updated_at_all_sql } AS updated_at_all"))
         .preload(tags: { tag_name: :wiki_page })
         .with_attached_thumbnail
-        .select("posts.*, #{ sort_sql } AS sort_ts")
-        .order(Arel.sql("#{ sort_sql } DESC"))
-    posts =
-        if cursor
-          q.where("#{ sort_sql } < ?", Time.iso8601(cursor)).limit(limit + 1)
+
+    q = q.where('posts.url LIKE ?', "%#{ url }%") if url
+    q = q.where('posts.title LIKE ?', "%#{ title }%") if title
+    if original_created_from
+      q = q.where('posts.original_created_before > ?', original_created_from)
+    end
+    if original_created_to
+      q = q.where('posts.original_created_from <= ?', original_created_to)
+    end
+    q = q.where('posts.created_at >= ?', created_between[0]) if created_between[0]
+    q = q.where('posts.created_at <= ?', created_between[1]) if created_between[1]
+    if updated_between[0]
+      q = q.where("#{ updated_at_all_sql } >= ?", updated_between[0])
+    end
+    if updated_between[1]
+      q = q.where("#{ updated_at_all_sql } <= ?", updated_between[1])
+    end
+
+    sort_sql =
+        if order[0] == 'original_created_at'
+          'COALESCE(posts.original_created_before - INTERVAL 1 MINUTE,' +
+          'posts.original_created_from,' +
+          'posts.created_at) ' +
+          order[1]
         else
-          q.limit(limit).offset(offset)
+          "posts.#{ order[0] } #{ order[1] }"
         end
-        .to_a
+    posts = q.order(Arel.sql("#{ sort_sql }")).limit(limit).offset(offset).to_a
 
-    next_cursor = nil
-    if cursor && posts.length > limit
-      next_cursor = posts.last.read_attribute('sort_ts').iso8601(6)
-      posts = posts.first(limit)
-    end
+    q = q.except(:select, :order)
 
     render json: { posts: posts.map { |post|
-      PostRepr.base(post).tap do |json|
+      PostRepr.base(post).merge(updated_at: post.updated_at_all).tap do |json|
         json['thumbnail'] =
             if post.thumbnail.attached?
               rails_storage_proxy_url(post.thumbnail, only_path: false)
@@ -44,11 +86,7 @@ class PostsController < ApplicationController
               nil
             end
       end
-    }, count: if filtered_posts.group_values.present?
-      filtered_posts.count.size
-    else
-      filtered_posts.count
-    end, next_cursor: }
+    }, count: q.group_values.present? ? q.count.size : q.count }
   end
 
   def random
@@ -63,7 +101,7 @@ class PostsController < ApplicationController
   end
 
   def show
-    post = Post.includes(tags: { tag_name: :wiki_page }).find(params[:id])
+    post = Post.includes(tags: { tag_name: :wiki_page }).find_by(id: params[:id])
     return head :not_found unless post
 
     viewed = current_user&.viewed?(post) || false
@@ -84,7 +122,7 @@ class PostsController < ApplicationController
     title = params[:title].presence
     url = params[:url]
     thumbnail = params[:thumbnail]
-    tag_names = params[:tags].to_s.split(' ')
+    tag_names = params[:tags].to_s.split
     original_created_from = params[:original_created_from]
     original_created_before = params[:original_created_before]
 
@@ -125,7 +163,7 @@ class PostsController < ApplicationController
     return head :forbidden unless current_user.member?
 
     title = params[:title].presence
-    tag_names = params[:tags].to_s.split(' ')
+    tag_names = params[:tags].to_s.split
     original_created_from = params[:original_created_from]
     original_created_before = params[:original_created_before]
 
@@ -192,7 +230,7 @@ class PostsController < ApplicationController
   private
 
   def filtered_posts
-    tag_names = params[:tags].to_s.split(' ')
+    tag_names = params[:tags].to_s.split
     match_type = params[:match]
     if tag_names.present?
       filter_posts_by_tags(tag_names, match_type)
diff --git a/backend/spec/requests/posts_spec.rb b/backend/spec/requests/posts_spec.rb
index 7ccdb52..c8621b1 100644
--- a/backend/spec/requests/posts_spec.rb
+++ b/backend/spec/requests/posts_spec.rb
@@ -1,7 +1,8 @@
+include ActiveSupport::Testing::TimeHelpers
+
 require 'rails_helper'
 require 'set'
 
-
 RSpec.describe 'Posts API', type: :request do
   # create / update で thumbnail.attach は走るが、
   # resized_thumbnail! が MiniMagick 依存でコケやすいので request spec ではスタブしとくのが無難。
@@ -114,6 +115,204 @@ RSpec.describe 'Posts API', type: :request do
         expect(json.fetch('count')).to eq(0)
       end
     end
+
+    context 'when url is provided' do
+      let!(:url_hit_post) do
+        Post.create!(uploaded_user: user, title: 'url hit',
+                     url: 'https://example.com/needle-url-xyz').tap do |p|
+          PostTag.create!(post: p, tag:)
+        end
+      end
+
+      let!(:url_miss_post) do
+        Post.create!(uploaded_user: user, title: 'url miss',
+                     url: 'https://example.com/other-url').tap do |p|
+          PostTag.create!(post: p, tag:)
+        end
+      end
+
+      it 'filters posts by url substring' do
+        get '/posts', params: { url: 'needle-url-xyz' }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(url_hit_post.id)
+        expect(ids).not_to include(url_miss_post.id)
+        expect(json.fetch('count')).to eq(1)
+      end
+    end
+
+    context 'when title is provided' do
+      let!(:title_hit_post) do
+        Post.create!(uploaded_user: user, title: 'needle-title-xyz',
+                     url: 'https://example.com/title-hit').tap do |p|
+          PostTag.create!(post: p, tag:)
+        end
+      end
+
+      let!(:title_miss_post) do
+        Post.create!(uploaded_user: user, title: 'other title',
+                     url: 'https://example.com/title-miss').tap do |p|
+          PostTag.create!(post: p, tag:)
+        end
+      end
+
+      it 'filters posts by title substring' do
+        get '/posts', params: { title: 'needle-title-xyz' }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(title_hit_post.id)
+        expect(ids).not_to include(title_miss_post.id)
+        expect(json.fetch('count')).to eq(1)
+      end
+    end
+
+    context 'when created_from/created_to are provided' do
+      let(:t_created_hit) { Time.zone.local(2010, 1, 5, 12, 0, 0) }
+      let(:t_created_miss) { Time.zone.local(2012, 1, 5, 12, 0, 0) }
+
+      let!(:created_hit_post) do
+        travel_to(t_created_hit) do
+          Post.create!(uploaded_user: user, title: 'created hit',
+                       url: 'https://example.com/created-hit').tap do |p|
+            PostTag.create!(post: p, tag:)
+          end
+        end
+      end
+
+      let!(:created_miss_post) do
+        travel_to(t_created_miss) do
+          Post.create!(uploaded_user: user, title: 'created miss',
+                       url: 'https://example.com/created-miss').tap do |p|
+            PostTag.create!(post: p, tag:)
+          end
+        end
+      end
+
+      it 'filters posts by created_at range' do
+        get '/posts', params: {
+          created_from: Time.zone.local(2010, 1, 1, 0, 0, 0).iso8601,
+          created_to: Time.zone.local(2010, 12, 31, 23, 59, 59).iso8601
+        }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(created_hit_post.id)
+        expect(ids).not_to include(created_miss_post.id)
+        expect(json.fetch('count')).to eq(1)
+      end
+    end
+
+    context 'when updated_from/updated_to are provided' do
+      let(:t0) { Time.zone.local(2011, 2, 1, 12, 0, 0) }
+      let(:t1) { Time.zone.local(2011, 2, 10, 12, 0, 0) }
+
+      let!(:updated_hit_post) do
+        p = nil
+        travel_to(t0) do
+          p = Post.create!(uploaded_user: user, title: 'updated hit',
+                           url: 'https://example.com/updated-hit').tap do |pp|
+            PostTag.create!(post: pp, tag:)
+          end
+        end
+        travel_to(t1) do
+          p.update!(title: 'updated hit v2')
+        end
+        p
+      end
+
+      let!(:updated_miss_post) do
+        travel_to(Time.zone.local(2013, 1, 1, 12, 0, 0)) do
+          Post.create!(uploaded_user: user, title: 'updated miss',
+                       url: 'https://example.com/updated-miss').tap do |p|
+            PostTag.create!(post: p, tag:)
+          end
+        end
+      end
+
+      it 'filters posts by updated_at range' do
+        get '/posts', params: {
+          updated_from: Time.zone.local(2011, 2, 5, 0, 0, 0).iso8601,
+          updated_to: Time.zone.local(2011, 2, 20, 23, 59, 59).iso8601
+        }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(updated_hit_post.id)
+        expect(ids).not_to include(updated_miss_post.id)
+        expect(json.fetch('count')).to eq(1)
+      end
+    end
+
+    context 'when original_created_from/original_created_to are provided' do
+      # 注意: controller の現状ロジックに合わせてる
+      # original_created_from は `original_created_before > ?`
+      # original_created_to   は `original_created_from <= ?`
+
+      let!(:oc_hit_post) do
+        Post.create!(uploaded_user: user, title: 'oc hit',
+                     url: 'https://example.com/oc-hit',
+                     original_created_from: Time.zone.local(2015, 1, 1, 0, 0, 0),
+                     original_created_before: Time.zone.local(2015, 1, 10, 0, 0, 0)).tap do |p|
+          PostTag.create!(post: p, tag:)
+        end
+      end
+
+      # original_created_from の条件は「original_created_before > param」なので、
+      # before が param 以下になるようにする（ただし before >= from は守る）
+      let!(:oc_miss_post_for_from) do
+        Post.create!(
+          uploaded_user: user,
+          title: 'oc miss for from',
+          url: 'https://example.com/oc-miss-from',
+          original_created_from: Time.zone.local(2014, 12, 1, 0, 0, 0),
+          original_created_before: Time.zone.local(2015, 1, 1, 0, 0, 0)
+        ).tap { |p| PostTag.create!(post: p, tag:) }
+      end
+
+      # original_created_to の条件は「original_created_from <= param」なので、
+      # from が param より後になるようにする（before >= from は守る）
+      let!(:oc_miss_post_for_to) do
+        Post.create!(
+          uploaded_user: user,
+          title: 'oc miss for to',
+          url: 'https://example.com/oc-miss-to',
+          original_created_from: Time.zone.local(2015, 2, 1, 0, 0, 0),
+          original_created_before: Time.zone.local(2015, 2, 10, 0, 0, 0)
+        ).tap { |p| PostTag.create!(post: p, tag:) }
+      end
+
+      it 'filters posts by original_created_from (current controller behavior)' do
+        get '/posts', params: {
+          original_created_from: Time.zone.local(2015, 1, 5, 0, 0, 0).iso8601
+        }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(oc_hit_post.id)
+        expect(ids).not_to include(oc_miss_post_for_from.id)
+        expect(json.fetch('count')).to eq(2)
+      end
+
+      it 'filters posts by original_created_to (current controller behavior)' do
+        get '/posts', params: {
+          original_created_to: Time.zone.local(2015, 1, 15, 0, 0, 0).iso8601
+        }
+
+        expect(response).to have_http_status(:ok)
+        ids = json.fetch('posts').map { |p| p['id'] }
+
+        expect(ids).to include(oc_hit_post.id)
+        expect(ids).not_to include(oc_miss_post_for_to.id)
+        expect(json.fetch('count')).to eq(2)
+      end
+    end
   end
 
   describe 'GET /posts/:id' do
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 98fa8ce..f7c9545 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -16,6 +16,7 @@ import PostDetailPage from '@/pages/posts/PostDetailPage'
 import PostHistoryPage from '@/pages/posts/PostHistoryPage'
 import PostListPage from '@/pages/posts/PostListPage'
 import PostNewPage from '@/pages/posts/PostNewPage'
+import PostSearchPage from '@/pages/posts/PostSearchPage'
 import ServiceUnavailable from '@/pages/ServiceUnavailable'
 import SettingPage from '@/pages/users/SettingPage'
 import WikiDetailPage from '@/pages/wiki/WikiDetailPage'
@@ -42,6 +43,7 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	    <Route path="/" element={<Navigate to="/posts" replace/>}/>
 	    <Route path="/posts" element={<PostListPage/>}/>
 	    <Route path="/posts/new" element={<PostNewPage user={user}/>}/>
+	    <Route path="/posts/search" element={<PostSearchPage/>}/>
 	    <Route path="/posts/:id" element={<PostDetailRoute user={user}/>}/>
 	    <Route path="/posts/changes" element={<PostHistoryPage/>}/>
 	    <Route path="/tags/nico" element={<NicoTagListPage user={user}/>}/>
diff --git a/frontend/src/components/PostFormTagsArea.tsx b/frontend/src/components/PostFormTagsArea.tsx
index c7775af..92450c1 100644
--- a/frontend/src/components/PostFormTagsArea.tsx
+++ b/frontend/src/components/PostFormTagsArea.tsx
@@ -1,3 +1,5 @@
+// TODO: TagSearch と共通化する．
+
 import { useRef, useState } from 'react'
 
 import TagSearchBox from '@/components/TagSearchBox'
@@ -81,9 +83,7 @@ export default (({ tags, setTags }: Props) => {
 	      const pos = (ev.target as HTMLTextAreaElement).selectionStart
 	      await recompute (pos)
 	    }}
-	    onFocus={() => {
-	      setFocused (true)
-	    }}
+	    onFocus={() => setFocused (true)}
 	    onBlur={() => {
 	      setFocused (false)
 	      setSuggestionsVsbl (false)
diff --git a/frontend/src/components/TagDetailSidebar.tsx b/frontend/src/components/TagDetailSidebar.tsx
index 64dbfe3..b4be734 100644
--- a/frontend/src/components/TagDetailSidebar.tsx
+++ b/frontend/src/components/TagDetailSidebar.tsx
@@ -19,6 +19,7 @@ import SidebarComponent from '@/components/layout/SidebarComponent'
 import { toast } from '@/components/ui/use-toast'
 import { CATEGORIES } from '@/consts'
 import { apiDelete, apiGet, apiPatch, apiPost } from '@/lib/api'
+import { dateString, originalCreatedAtString } from '@/lib/utils'
 
 import type { DragEndEvent } from '@dnd-kit/core'
 import type { FC, MutableRefObject, ReactNode } from 'react'
@@ -343,7 +344,7 @@ export default (({ post }: Props) => {
 		       : 'bot操作'}
 		    </li>
 		    */}
-		    <li>耕作日時: {(new Date (post.createdAt)).toLocaleString ()}</li>
+		    <li>耕作日時: {dateString (post.createdAt)}</li>
 		    <li>
 		      <>リンク: </>
 		      <a
@@ -355,20 +356,14 @@ export default (({ post }: Props) => {
 		      </a>
 		    </li>
 		    <li>
-		      {/* TODO: 表示形式きしょすぎるので何とかする */}
 		      <>オリジナルの投稿日時: </>
-		      {!(post.originalCreatedFrom) && !(post.originalCreatedBefore)
-		       ? '不明'
-		       : (
-			  <>
-			    {post.originalCreatedFrom
-			     && `${ (new Date (post.originalCreatedFrom)).toLocaleString () } 以降 `}
-			    {post.originalCreatedBefore
-			     && `${ (new Date (post.originalCreatedBefore)).toLocaleString () } より前`}
-			  </>)}
+		      {originalCreatedAtString (post.originalCreatedFrom,
+						post.originalCreatedBefore)}
 		    </li>
 		    <li>
-		      <PrefetchLink to={`/posts/changes?id=${ post.id }`}>履歴</PrefetchLink>
+		      <PrefetchLink to={`/posts/changes?id=${ post.id }`}>
+			履歴
+		      </PrefetchLink>
 		    </li>
 		  </ul>
 		</div>)}
diff --git a/frontend/src/components/TagSearch.tsx b/frontend/src/components/TagSearch.tsx
index 6e7a8bd..13f72a4 100644
--- a/frontend/src/components/TagSearch.tsx
+++ b/frontend/src/components/TagSearch.tsx
@@ -1,3 +1,5 @@
+// TODO: タグ入力系すべてに同様の処理あるため共通化する．
+
 import { useEffect, useState } from 'react'
 import { useNavigate, useLocation } from 'react-router-dom'
 
diff --git a/frontend/src/components/TopNav.tsx b/frontend/src/components/TopNav.tsx
index 144f517..06c30cf 100644
--- a/frontend/src/components/TopNav.tsx
+++ b/frontend/src/components/TopNav.tsx
@@ -69,8 +69,9 @@ export default (({ user }: Props) => {
   const menu: Menu = [
       { name: '広場', to: '/posts', subMenu: [
 	  { name: '一覧', to: '/posts' },
+	  { name: '検索', to: '/posts/search' },
 	  { name: '投稿追加', to: '/posts/new' },
-	  { name: '耕作履歴', to: '/posts/changes' },
+	  { name: '履歴', to: '/posts/changes' },
 	  { name: 'ヘルプ', to: '/wiki/ヘルプ:広場' }] },
       { name: 'タグ', to: '/tags', subMenu: [
 	  { name: 'タグ一覧', to: '/tags', visible: false },
diff --git a/frontend/src/consts.ts b/frontend/src/consts.ts
index 214a19b..13968d2 100644
--- a/frontend/src/consts.ts
+++ b/frontend/src/consts.ts
@@ -3,13 +3,23 @@ import type { Category } from 'types'
 export const LIGHT_COLOUR_SHADE = 800
 export const DARK_COLOUR_SHADE = 300
 
-export const CATEGORIES = ['deerjikist',
-			   'meme',
-			   'character',
-			   'general',
-			   'material',
-			   'meta',
-			   'nico'] as const
+export const CATEGORIES = [
+    'deerjikist',
+    'meme',
+    'character',
+    'general',
+    'material',
+    'meta',
+    'nico',
+    ] as const
+
+export const FETCH_POSTS_ORDER_FIELDS = [
+    'title',
+    'url',
+    'original_created_at',
+    'created_at',
+    'updated_at',
+    ] as const
 
 export const TAG_COLOUR = {
     deerjikist: 'rose',
@@ -18,10 +28,13 @@ export const TAG_COLOUR = {
     general:    'cyan',
     material:   'orange',
     meta:       'yellow',
-    nico:       'gray' } as const satisfies Record<Category, string>
+    nico:       'gray',
+    } as const satisfies Record<Category, string>
 
 export const USER_ROLES = ['admin', 'member', 'guest'] as const
 
-export const ViewFlagBehavior = { OnShowedDetail: 1,
-				  OnClickedLink:  2,
-				  NotAuto:        3 } as const
+export const ViewFlagBehavior = {
+    OnShowedDetail: 1,
+    OnClickedLink:  2,
+    NotAuto:        3,
+    } as const
diff --git a/frontend/src/lib/posts.ts b/frontend/src/lib/posts.ts
index 99c95f3..04ec1ba 100644
--- a/frontend/src/lib/posts.ts
+++ b/frontend/src/lib/posts.ts
@@ -1,25 +1,28 @@
 import { apiDelete, apiGet, apiPost } from '@/lib/api'
 
-import type { Post, PostTagChange } from '@/types'
+import type { FetchPostsParams, Post, PostTagChange } from '@/types'
 
 
 export const fetchPosts = async (
-    { tags, match, page, limit, cursor }: {
-	tags:     string
-	match:    'any' | 'all'
-	page?:    number
-	limit?:   number
-	cursor?:  string }
+    { url, title, tags, match, createdFrom, createdTo, updatedFrom, updatedTo,
+      originalCreatedFrom, originalCreatedTo, page, limit, order }: FetchPostsParams
 ): Promise<{
-    posts:      Post[]
-    count:      number
-    nextCursor: string }> =>
+    posts:  Post[]
+    count:  number }> =>
 	await apiGet ('/posts', { params: {
-	    tags,
-	    match,
+	    ...(url && { url }),
+	    ...(title && { title }),
+	    ...(tags && { tags }),
+	    ...(match && { match }),
+	    ...(createdFrom && { created_from: createdFrom }),
+	    ...(createdTo && { created_to: createdTo }),
+	    ...(updatedFrom && { updated_from: updatedFrom }),
+	    ...(updatedTo && { updated_to: updatedTo }),
+	    ...(originalCreatedFrom && { original_created_from: originalCreatedFrom }),
+	    ...(originalCreatedTo && { original_created_to: originalCreatedTo }),
 	    ...(page && { page }),
 	    ...(limit && { limit }),
-	    ...(cursor && { cursor }) } })
+	    ...(order && { order }) } })
 
 
 export const fetchPost = async (id: string): Promise<Post> => await apiGet (`/posts/${ id }`)
diff --git a/frontend/src/lib/prefetchers.ts b/frontend/src/lib/prefetchers.ts
index d61291e..4461ae7 100644
--- a/frontend/src/lib/prefetchers.ts
+++ b/frontend/src/lib/prefetchers.ts
@@ -8,6 +8,8 @@ import { fetchWikiPage,
 	 fetchWikiPageByTitle,
 	 fetchWikiPages } from '@/lib/wiki'
 
+import type { FetchPostsOrder } from '@/types'
+
 type Prefetcher = (qc: QueryClient, url: URL) => Promise<void>
 
 const mPost = match<{ id: string }> ('/posts/:id')
@@ -59,7 +61,20 @@ const prefetchWikiPageShow: Prefetcher = async (qc, url) => {
   if (version)
     return
 
-  const p = { tags: effectiveTitle, match: 'all', page: 1, limit: 8 } as const
+  const p = {
+      tags: effectiveTitle,
+      match: 'all',
+      page: 1,
+      limit: 8,
+      url: '',
+      title: '',
+      originalCreatedFrom: '',
+      originalCreatedTo: '',
+      createdFrom: '',
+      createdTo: '',
+      updatedFrom: '',
+      updatedTo: '',
+      order: 'original_created_at:desc' } as const
   await qc.prefetchQuery ({
       queryKey: postsKeys.index (p),
       queryFn:  () => fetchPosts (p) })
@@ -68,13 +83,27 @@ const prefetchWikiPageShow: Prefetcher = async (qc, url) => {
 
 const prefetchPostsIndex: Prefetcher = async (qc, url) => {
   const tags = url.searchParams.get ('tags') ?? ''
-  const m = url.searchParams.get ('match') === 'any' ? 'any' : 'all'
+  const qURL = url.searchParams.get ('url') ?? ''
+  const title = url.searchParams.get ('title') ?? ''
+  const originalCreatedFrom = url.searchParams.get ('original_created_from') ?? ''
+  const originalCreatedTo = url.searchParams.get ('original_created_to') ?? ''
+  const createdFrom = url.searchParams.get ('created_from') ?? ''
+  const createdTo = url.searchParams.get ('created_to') ?? ''
+  const updatedFrom = url.searchParams.get ('updated_from') ?? ''
+  const updatedTo = url.searchParams.get ('updated_to') ?? ''
+  const m: 'all' | 'any' = url.searchParams.get ('match') === 'any' ? 'any' : 'all'
   const page = Number (url.searchParams.get ('page') || 1)
   const limit = Number (url.searchParams.get ('limit') || 20)
+  const order = (url.searchParams.get ('order') ?? 'original_created_at:desc') as FetchPostsOrder
+
+  const keys = {
+      tags, match: m, page, limit, url: qURL, title,
+      originalCreatedFrom, originalCreatedTo, createdFrom, createdTo,
+      updatedFrom, updatedTo, order }
 
   await qc.prefetchQuery ({
-      queryKey: postsKeys.index ({ tags, match: m, page, limit }),
-      queryFn:  () => fetchPosts ({ tags, match: m, page, limit }) })
+      queryKey: postsKeys.index (keys),
+      queryFn:  () => fetchPosts (keys) })
 }
 
 
@@ -103,8 +132,9 @@ const prefetchPostChanges: Prefetcher = async (qc, url) => {
 
 
 export const routePrefetchers: { test: (u: URL) => boolean; run: Prefetcher }[] = [
-    { test: u => u.pathname === '/' || u.pathname === '/posts', run: prefetchPostsIndex },
-    { test: u => (!(['/posts/new', '/posts/changes'].includes (u.pathname))
+    { test: u => ['/', '/posts', '/posts/search'].includes (u.pathname),
+      run: prefetchPostsIndex },
+    { test: u => (!(['/posts/new', '/posts/changes', '/posts/search'].includes (u.pathname))
 		  && Boolean (mPost (u.pathname))),
       run: prefetchPostShow },
     { test: u => u.pathname === '/posts/changes', run: prefetchPostChanges },
@@ -119,5 +149,6 @@ export const prefetchForURL = async (qc: QueryClient, urlLike: string): Promise<
   const r = routePrefetchers.find (x => x.test (u))
   if (!(r))
     return
+
   await r.run (qc, u)
 }
diff --git a/frontend/src/lib/queryKeys.ts b/frontend/src/lib/queryKeys.ts
index 909d54e..d8cbeef 100644
--- a/frontend/src/lib/queryKeys.ts
+++ b/frontend/src/lib/queryKeys.ts
@@ -1,7 +1,8 @@
+import type { FetchPostsParams } from '@/types'
+
 export const postsKeys = {
     root:     ['posts'] as const,
-    index:    (p: { tags: string; match: 'any' | 'all'; page: number; limit: number }) =>
-		  ['posts', 'index', p] as const,
+    index:    (p: FetchPostsParams) => ['posts', 'index', p] as const,
     show:     (id: string) => ['posts', id] as const,
     related:  (id: string) => ['related', id] as const,
     changes:  (p: { id?: string; page: number; limit: number }) =>
diff --git a/frontend/src/lib/utils.ts b/frontend/src/lib/utils.ts
index 871bdd6..95caded 100644
--- a/frontend/src/lib/utils.ts
+++ b/frontend/src/lib/utils.ts
@@ -4,4 +4,23 @@ import { twMerge } from 'tailwind-merge'
 import type { ClassValue } from 'clsx'
 
 
+export const toDate = (d: string | Date): Date => typeof d === 'string' ? new Date (d) : d
+
+
 export const cn = (...inputs: ClassValue[]) => twMerge (clsx (...inputs))
+
+
+export const dateString = (d: string | Date): string =>
+    toDate (d).toLocaleString ('ja-JP-u-ca-japanese')
+
+
+// TODO: 表示形式きしょすぎるので何とかする
+export const originalCreatedAtString = (
+    f:  string | Date | null,
+    b:  string | Date | null,
+): string =>
+    ([f ? `${ dateString (f) } 以降` : '',
+      b ? `${ dateString (b) } より前` : '']
+     .filter (Boolean)
+     .join (' '))
+    || '不明'
diff --git a/frontend/src/pages/posts/PostHistoryPage.tsx b/frontend/src/pages/posts/PostHistoryPage.tsx
index 3fd444e..7fe2202 100644
--- a/frontend/src/pages/posts/PostHistoryPage.tsx
+++ b/frontend/src/pages/posts/PostHistoryPage.tsx
@@ -1,4 +1,6 @@
 import { useQuery } from '@tanstack/react-query'
+import { motion } from 'framer-motion'
+import { useEffect } from 'react'
 import { Helmet } from 'react-helmet-async'
 import { useLocation } from 'react-router-dom'
 
@@ -10,7 +12,7 @@ import MainArea from '@/components/layout/MainArea'
 import { SITE_TITLE } from '@/config'
 import { fetchPostChanges } from '@/lib/posts'
 import { postsKeys } from '@/lib/queryKeys'
-import { cn } from '@/lib/utils'
+import { cn, dateString } from '@/lib/utils'
 
 import type { FC } from 'react'
 
@@ -31,6 +33,10 @@ export default (() => {
   const changes = data?.changes ?? []
   const totalPages = data ? Math.ceil (data.count / limit) : 0
 
+  useEffect (() => {
+    document.querySelector ('table')?.scrollIntoView ({ behavior: 'smooth' })
+  }, [location.search])
+
   return (
       <MainArea>
 	<Helmet>
@@ -72,10 +78,17 @@ export default (() => {
 			      <td className="align-top p-2 bg-white dark:bg-[#242424] border-r"
 				  rowSpan={rowsCnt}>
 				<PrefetchLink to={`/posts/${ change.post.id }`}>
-				  <img src={change.post.thumbnail || change.post.thumbnailBase || undefined}
-				       alt={change.post.title || change.post.url}
-				       title={change.post.title || change.post.url || undefined}
-				       className="w-40"/>
+				  <motion.div
+				      layoutId={`page-${ change.post.id }`}
+				      transition={{ type: 'spring',
+						    stiffness: 500,
+						    damping: 40,
+						    mass: .5 }}>
+				    <img src={change.post.thumbnail || change.post.thumbnailBase || undefined}
+					 alt={change.post.title || change.post.url}
+					 title={change.post.title || change.post.url || undefined}
+					 className="w-40"/>
+				  </motion.div>
 				</PrefetchLink>
 			      </td>)}
 			  <td className="p-2">
@@ -83,12 +96,14 @@ export default (() => {
 			    {`を${ change.changeType === 'add' ? '記載' : '消除' }`}
 			  </td>
 			  <td className="p-2">
-			    {change.user ? (
+			    {change.user
+			     ? (
 				<PrefetchLink to={`/users/${ change.user.id }`}>
 				  {change.user.name}
-				</PrefetchLink>) : 'bot 操作'}
+				</PrefetchLink>)
+			     : 'bot 操作'}
 			    <br/>
-			    {change.timestamp}
+			    {dateString (change.timestamp)}
 			  </td>
 			</tr>)
 		  })}
diff --git a/frontend/src/pages/posts/PostListPage.tsx b/frontend/src/pages/posts/PostListPage.tsx
index 8dc20d6..70e3e68 100644
--- a/frontend/src/pages/posts/PostListPage.tsx
+++ b/frontend/src/pages/posts/PostListPage.tsx
@@ -35,11 +35,16 @@ export default (() => {
   const page = Number (query.get ('page') ?? 1)
   const limit = Number (query.get ('limit') ?? 20)
 
+  const keys = {
+      tags: tagsKey, match, page, limit,
+      url: '', title: '', originalCreatedFrom: '', originalCreatedTo: '',
+      createdFrom: '', createdTo: '', updatedFrom: '', updatedTo: '',
+      order: 'original_created_at:desc' } as const
   const { data, isLoading: loading } = useQuery ({
-      queryKey: postsKeys.index ({ tags: tagsKey, match, page, limit }),
-      queryFn:  () => fetchPosts ({ tags: tagsKey, match, page, limit }) })
+      queryKey: postsKeys.index (keys),
+      queryFn:  () => fetchPosts (keys) })
   const posts = data?.posts ?? []
-  const cursor = data?.nextCursor ?? ''
+  const cursor = ''
   const totalPages = data ? Math.ceil (data.count / limit) : 0
 
   useLayoutEffect (() => {
diff --git a/frontend/src/pages/posts/PostSearchPage.tsx b/frontend/src/pages/posts/PostSearchPage.tsx
new file mode 100644
index 0000000..727dced
--- /dev/null
+++ b/frontend/src/pages/posts/PostSearchPage.tsx
@@ -0,0 +1,410 @@
+import { useQuery } from '@tanstack/react-query'
+import { motion } from 'framer-motion'
+import { useEffect, useMemo, useState } from 'react'
+import { Helmet } from 'react-helmet-async'
+import { useLocation, useNavigate } from 'react-router-dom'
+
+import PrefetchLink from '@/components/PrefetchLink'
+import TagLink from '@/components/TagLink'
+import TagSearchBox from '@/components/TagSearchBox'
+import DateTimeField from '@/components/common/DateTimeField'
+import Label from '@/components/common/Label'
+import PageTitle from '@/components/common/PageTitle'
+import Pagination from '@/components/common/Pagination'
+import MainArea from '@/components/layout/MainArea'
+import { SITE_TITLE } from '@/config'
+import { apiGet } from '@/lib/api'
+import { fetchPosts } from '@/lib/posts'
+import { postsKeys } from '@/lib/queryKeys'
+import { dateString, originalCreatedAtString } from '@/lib/utils'
+
+import type { FC, ChangeEvent, FormEvent, KeyboardEvent } from 'react'
+
+import type { FetchPostsOrder,
+	      FetchPostsOrderField,
+	      FetchPostsParams,
+	      Tag } from '@/types'
+
+
+const setIf = (qs: URLSearchParams, k: string, v: string | null) => {
+  const t = v?.trim ()
+  if (t)
+    qs.set (k, t)
+}
+
+
+export default (() => {
+  const location = useLocation ()
+
+  const navigate = useNavigate ()
+
+  const query = useMemo (() => new URLSearchParams (location.search),
+			 [location.search])
+
+  const page = Number (query.get ('page') ?? 1)
+  const limit = Number (query.get ('limit') ?? 20)
+
+  const qURL = query.get ('url') ?? ''
+  const qTitle = query.get ('title') ?? ''
+  const qTags = query.get ('tags') ?? ''
+  const qMatch: 'all' | 'any' = query.get ('match') === 'any' ? 'any' : 'all'
+  const qOriginalCreatedFrom = query.get ('original_created_from') ?? ''
+  const qOriginalCreatedTo = query.get ('original_created_to') ?? ''
+  const qCreatedFrom = query.get ('created_from') ?? ''
+  const qCreatedTo = query.get ('created_to') ?? ''
+  const qUpdatedFrom = query.get ('updated_from') ?? ''
+  const qUpdatedTo = query.get ('updated_to') ?? ''
+  const order = (query.get ('order') || 'original_created_at:desc') as FetchPostsOrder
+
+  const [activeIndex, setActiveIndex] = useState (-1)
+  const [createdFrom, setCreatedFrom] = useState<string | null> (null)
+  const [createdTo, setCreatedTo] = useState<string | null> (null)
+  const [matchType, setMatchType] = useState<'all' | 'any'> ('all')
+  const [originalCreatedFrom, setOriginalCreatedFrom] = useState<string | null> (null)
+  const [originalCreatedTo, setOriginalCreatedTo] = useState<string | null> (null)
+  const [suggestions, setSuggestions] = useState<Tag[]> ([])
+  const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
+  const [tagsStr, setTagsStr] = useState ('')
+  const [title, setTitle] = useState ('')
+  const [updatedFrom, setUpdatedFrom] = useState<string | null> (null)
+  const [updatedTo, setUpdatedTo] = useState<string | null> (null)
+  const [url, setURL] = useState ('')
+
+  const keys: FetchPostsParams = {
+      tags: qTags, match: qMatch, page, limit,
+      url: qURL,
+      title: qTitle,
+      originalCreatedFrom: qOriginalCreatedFrom,
+      originalCreatedTo: qOriginalCreatedTo,
+      createdFrom: qCreatedFrom,
+      createdTo: qCreatedTo,
+      updatedFrom: qUpdatedFrom,
+      updatedTo: qUpdatedTo,
+      order }
+  const { data, isLoading: loading } = useQuery ({
+      queryKey: postsKeys.index (keys),
+      queryFn: () => fetchPosts (keys) })
+  const results = data?.posts ?? []
+  const totalPages = data ? Math.ceil (data.count / limit) : 0
+
+  useEffect (() => {
+    setURL (qURL ?? '')
+    setTitle (qTitle ?? '')
+    setTagsStr (qTags ?? '')
+    setMatchType (qMatch ?? 'all')
+    setOriginalCreatedFrom (qOriginalCreatedFrom)
+    setOriginalCreatedTo (qOriginalCreatedTo)
+    setCreatedFrom (qCreatedFrom)
+    setCreatedTo (qCreatedTo)
+    setUpdatedFrom (qUpdatedFrom)
+    setUpdatedTo (qUpdatedTo)
+
+    document.querySelector ('table')?.scrollIntoView ({ behavior: 'smooth' })
+  }, [location.search])
+
+  const SortHeader = ({ by, label }: { by: FetchPostsOrderField; label: string }) => {
+    const [fld, dir] = order.split (':')
+
+    const qs = new URLSearchParams (location.search)
+    const nextDir =
+	(by === fld)
+	? (dir === 'asc' ? 'desc' : 'asc')
+	: (['title', 'url'].includes (by) ? 'asc' : 'desc')
+    qs.set ('order', `${ by }:${ nextDir }`)
+    qs.set ('page', '1')
+
+    return (
+	<PrefetchLink
+	    className="text-inherit visited:text-inherit hover:text-inherit"
+	    to={`${ location.pathname }?${ qs.toString () }`}>
+	  <span className="font-bold">
+	    {label}
+	    {by === fld && (dir === 'asc' ? ' ▲' : ' ▼')}
+	  </span>
+	</PrefetchLink>)
+  }
+
+  // TODO: TagSearch からのコピペのため，共通化を考へる．
+  const whenChanged = async (ev: ChangeEvent<HTMLInputElement>) => {
+    setTagsStr (ev.target.value)
+
+    const q = ev.target.value.trim ().split (' ').at (-1)
+    if (!(q))
+      {
+	setSuggestions ([])
+	return
+      }
+
+    const data = await apiGet<Tag[]> ('/tags/autocomplete', { params: { q } })
+    setSuggestions (data.filter (t => t.postCount > 0))
+    if (suggestions.length > 0)
+      setSuggestionsVsbl (true)
+  }
+
+  // TODO: TagSearch からのコピペのため，共通化を考へる．
+  const handleKeyDown = (ev: KeyboardEvent<HTMLInputElement>) => {
+    switch (ev.key)
+    {
+    case 'ArrowDown':
+      ev.preventDefault ()
+      setActiveIndex (i => Math.min (i + 1, suggestions.length - 1))
+      setSuggestionsVsbl (true)
+      break
+
+    case 'ArrowUp':
+      ev.preventDefault ()
+      setActiveIndex (i => Math.max (i - 1, -1))
+      setSuggestionsVsbl (true)
+      break
+
+    case 'Enter':
+      if (activeIndex < 0)
+	break
+      ev.preventDefault ()
+      const selected = suggestions[activeIndex]
+      selected && handleTagSelect (selected)
+      break
+
+    case 'Escape':
+      ev.preventDefault ()
+      setSuggestionsVsbl (false)
+      break
+    }
+    if (ev.key === 'Enter' && (!(suggestionsVsbl) || activeIndex < 0))
+      {
+	setSuggestionsVsbl (false)
+      }
+  }
+
+  const search = async () => {
+    const qs = new URLSearchParams ()
+    setIf (qs, 'tags', tagsStr)
+    setIf (qs, 'url', url)
+    setIf (qs, 'title', title)
+    setIf (qs, 'original_created_from', originalCreatedFrom)
+    setIf (qs, 'original_created_to', originalCreatedTo)
+    setIf (qs, 'created_from', createdFrom)
+    setIf (qs, 'created_to', createdTo)
+    setIf (qs, 'updated_from', updatedFrom)
+    setIf (qs, 'updated_to', updatedTo)
+    qs.set ('match', matchType)
+    qs.set ('page', String ('1'))
+    qs.set ('order', order)
+    navigate (`${ location.pathname }?${ qs.toString () }`)
+  }
+
+  // TODO: TagSearch からのコピペのため，共通化を考へる．
+  const handleTagSelect = (tag: Tag) => {
+    const parts = tagsStr.split (' ')
+    parts[parts.length - 1] = tag.name
+    setTagsStr (parts.join (' ') + ' ')
+    setSuggestions ([])
+    setActiveIndex (-1)
+  }
+
+  const handleSearch = (e: FormEvent) => {
+    e.preventDefault ()
+    search ()
+  }
+
+  return (
+      <MainArea>
+	<Helmet>
+	  <title>広場検索 | {SITE_TITLE}</title>
+	</Helmet>
+
+	<div className="max-w-xl">
+	  <PageTitle>広場検索</PageTitle>
+
+	  <form onSubmit={handleSearch} className="space-y-2">
+	    {/* タイトル */}
+	    <div>
+	      <Label>タイトル</Label>
+	      <input
+		  type="text"
+		  value={title}
+		  onChange={e => setTitle (e.target.value)}
+		  className="w-full border p-2 rounded"/>
+	    </div>
+
+	    {/* URL */}
+	    <div>
+	      <Label>URL</Label>
+	      <input
+		  type="text"
+		  value={url}
+		  onChange={e => setURL (e.target.value)}
+		  className="w-full border p-2 rounded"/>
+	    </div>
+
+	    {/* タグ */}
+	    <div className="relative">
+	      <Label>タグ</Label>
+	      <input
+		  type="text"
+		  value={tagsStr}
+		  onChange={whenChanged}
+		  onFocus={() => setSuggestionsVsbl (true)}
+		  onBlur={() => setSuggestionsVsbl (false)}
+		  onKeyDown={handleKeyDown}
+		  className="w-full border p-2 rounded"/>
+	      <TagSearchBox
+		  suggestions={
+		      suggestionsVsbl && suggestions.length > 0 ? suggestions : [] as Tag[]}
+		  activeIndex={activeIndex}
+		  onSelect={handleTagSelect}/>
+	      <fieldset className="w-full my-2">
+		<label>検索区分：</label>
+		<label className="mx-2">
+		  <input
+		      type="radio"
+		      name="match-type"
+		      checked={matchType === 'all'}
+		      onChange={() => setMatchType ('all')}/>
+		  AND
+		</label>
+		<label className="mx-2">
+		  <input
+		      type="radio"
+		      name="match-type"
+		      checked={matchType === 'any'}
+		      onChange={() => setMatchType ('any')}/>
+		  OR
+		</label>
+	      </fieldset>
+	    </div>
+
+	    {/* オリジナルの投稿日時 */}
+	    <div>
+	      <Label>オリジナルの投稿日時</Label>
+	      <DateTimeField
+		  value={originalCreatedFrom ?? undefined}
+		  onChange={setOriginalCreatedFrom}/>
+	      <span className="mx-1">〜</span>
+	      <DateTimeField
+		  value={originalCreatedTo ?? undefined}
+		  onChange={setOriginalCreatedTo}/>
+	    </div>
+
+	    {/* 投稿日時 */}
+	    <div>
+	      <Label>投稿日時</Label>
+	      <DateTimeField
+		  value={createdFrom ?? undefined}
+		  onChange={setCreatedFrom}/>
+	      <span className="mx-1">〜</span>
+	      <DateTimeField
+		  value={createdTo ?? undefined}
+		  onChange={setCreatedTo}/>
+	    </div>
+
+	    {/* 更新日時 */}
+	    <div>
+	      <Label>更新日時</Label>
+	      <DateTimeField
+		  value={updatedFrom ?? undefined}
+		  onChange={setUpdatedFrom}/>
+	      <span className="mx-1">〜</span>
+	      <DateTimeField
+		  value={updatedTo ?? undefined}
+		  onChange={setUpdatedTo}/>
+	    </div>
+
+	    {/* 検索 */}
+	    <div className="py-3">
+	      <button
+		  type="submit"
+		  className="bg-blue-500 text-white px-4 py-2 rounded">
+		検索
+	      </button>
+	    </div>
+	  </form>
+	</div>
+
+	{loading ? 'Loading...' : (results.length > 0 ? (
+	    <div className="mt-4">
+	      <div className="overflow-x-auto">
+		<table className="w-full min-w-[1200px] table-fixed border-collapse">
+		  <colgroup>
+		    <col className="w-14"/>
+		    <col className="w-72"/>
+		    <col className="w-80"/>
+		    <col className="w-[24rem]"/>
+		    <col className="w-60"/>
+		    <col className="w-44"/>
+		    <col className="w-44"/>
+		  </colgroup>
+
+		  <thead className="border-b-2 border-black dark:border-white">
+		    <tr>
+		      <th className="p-2 text-left whitespace-nowrap">投稿</th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			<SortHeader by="title" label="タイトル"/>
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			<SortHeader by="url" label="URL"/>
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">タグ</th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			<SortHeader by="original_created_at" label="オリジナルの投稿日時"/>
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			<SortHeader by="created_at" label="投稿日時"/>
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			<SortHeader by="updated_at" label="更新日時"/>
+		      </th>
+		    </tr>
+		  </thead>
+		  <tbody>
+		    {results.map (row => (
+			<tr key={row.id} className={'even:bg-gray-100 dark:even:bg-gray-700'}>
+			  <td className="p-2">
+			    <PrefetchLink to={`/posts/${ row.id }`} title={row.title}>
+			      <motion.div
+				  layoutId={`page-${ row.id }`}
+				  transition={{ type: 'spring',
+						stiffness: 500,
+						damping: 40,
+						mass: .5 }}>
+				<img src={row.thumbnail || row.thumbnailBase || undefined}
+				     alt={row.title || row.url}
+				     title={row.title || row.url || undefined}
+				     className="w-8"/>
+			      </motion.div>
+			    </PrefetchLink>
+			  </td>
+			  <td className="p-2 truncate">
+			    <PrefetchLink to={`/posts/${ row.id }`} title={row.title}>
+			      {row.title}
+			    </PrefetchLink>
+			  </td>
+			  <td className="p-2 truncate">
+			    <a href={row.url}
+			       title={row.url}
+			       target="_blank"
+			       rel="noopener noreferrer nofollow">
+			      {row.url}
+			    </a>
+			  </td>
+			  <td className="p-2">
+			    {row.tags.map (t => (
+				<span key={t.id} className="mr-2">
+				  <TagLink tag={t} withWiki={false} withCount={false}/>
+				</span>))}
+			  </td>
+			  <td className="p-2">
+			    {originalCreatedAtString (row.originalCreatedFrom,
+						      row.originalCreatedBefore)}
+			  </td>
+			  <td className="p-2">{dateString (row.createdAt)}</td>
+			  <td className="p-2">{dateString (row.updatedAt)}</td>
+			</tr>))}
+		  </tbody>
+		</table>
+	      </div>
+
+	      <Pagination page={page} totalPages={totalPages}/>
+	    </div>) : '結果ないよ（笑）')}
+      </MainArea>)
+}) satisfies FC
diff --git a/frontend/src/pages/wiki/WikiDetailPage.tsx b/frontend/src/pages/wiki/WikiDetailPage.tsx
index eeb0b87..fd2c0b5 100644
--- a/frontend/src/pages/wiki/WikiDetailPage.tsx
+++ b/frontend/src/pages/wiki/WikiDetailPage.tsx
@@ -44,10 +44,15 @@ export default () => {
       queryKey: tagsKeys.show (effectiveTitle),
       queryFn:  () => fetchTagByName (effectiveTitle) })
 
+  const keys = {
+      tags: effectiveTitle, match: 'all', page: 1, limit: 8, url: '', title: '',
+      originalCreatedFrom: '', originalCreatedTo: '',
+      createdFrom: '', createdTo: '', updatedFrom: '', updatedTo: '',
+      order: 'original_created_at:desc' } as const
   const { data } = useQuery ({
       enabled:  Boolean (effectiveTitle) && !(version),
-      queryKey: postsKeys.index ({ tags: effectiveTitle, match: 'all', page: 1, limit: 8 }),
-      queryFn:  () => fetchPosts ({ tags: effectiveTitle, match: 'all', page: 1, limit: 8 }) })
+      queryKey: postsKeys.index (keys),
+      queryFn:  () => fetchPosts (keys) })
   const posts = data?.posts || []
 
   useEffect (() => {
diff --git a/frontend/src/pages/wiki/WikiHistoryPage.tsx b/frontend/src/pages/wiki/WikiHistoryPage.tsx
index 1ed278a..056e937 100644
--- a/frontend/src/pages/wiki/WikiHistoryPage.tsx
+++ b/frontend/src/pages/wiki/WikiHistoryPage.tsx
@@ -7,6 +7,7 @@ import PageTitle from '@/components/common/PageTitle'
 import MainArea from '@/components/layout/MainArea'
 import { SITE_TITLE } from '@/config'
 import { apiGet } from '@/lib/api'
+import { dateString } from '@/lib/utils'
 
 import type { WikiPageChange } from '@/types'
 
@@ -65,7 +66,7 @@ export default () => {
 		      {change.user.name}
 		    </PrefetchLink>
 		    <br/>
-		    {change.timestamp}
+		    {dateString (change.timestamp)}
 		  </td>
 		</tr>))}
 	  </tbody>
diff --git a/frontend/src/pages/wiki/WikiSearchPage.tsx b/frontend/src/pages/wiki/WikiSearchPage.tsx
index bc3e3e7..73f23a8 100644
--- a/frontend/src/pages/wiki/WikiSearchPage.tsx
+++ b/frontend/src/pages/wiki/WikiSearchPage.tsx
@@ -6,6 +6,7 @@ import PageTitle from '@/components/common/PageTitle'
 import MainArea from '@/components/layout/MainArea'
 import { SITE_TITLE } from '@/config'
 import { apiGet } from '@/lib/api'
+import { dateString } from '@/lib/utils'
 
 import type { FormEvent } from 'react'
 
@@ -84,7 +85,7 @@ export default () => {
 		      </PrefetchLink>
 		    </td>
 		    <td className="p-2">
-		      {page.updatedAt}
+		      {dateString (page.updatedAt)}
 		    </td>
 		  </tr>))}
 	    </tbody>
diff --git a/frontend/src/types.ts b/frontend/src/types.ts
index 5cf9f5d..d7b0afd 100644
--- a/frontend/src/types.ts
+++ b/frontend/src/types.ts
@@ -1,9 +1,31 @@
-import { CATEGORIES, USER_ROLES, ViewFlagBehavior } from '@/consts'
+import { CATEGORIES,
+	 FETCH_POSTS_ORDER_FIELDS,
+	 USER_ROLES,
+	 ViewFlagBehavior } from '@/consts'
 
 import type { ReactNode } from 'react'
 
 export type Category = typeof CATEGORIES[number]
 
+export type FetchPostsOrder = `${ FetchPostsOrderField }:${ 'asc' | 'desc' }`
+
+export type FetchPostsOrderField = typeof FETCH_POSTS_ORDER_FIELDS[number]
+
+export type FetchPostsParams = {
+    url:                  string
+    title:                string
+    tags:                 string
+    match:                'all' | 'any'
+    originalCreatedFrom:  string
+    originalCreatedTo:    string
+    createdFrom:          string
+    createdTo:            string
+    updatedFrom:          string
+    updatedTo:            string
+    page:                 number
+    limit:                number
+    order:                FetchPostsOrder }
+
 export type Menu = MenuItem[]
 
 export type MenuItem = {
@@ -25,9 +47,10 @@ export type Post = {
     tags:                   Tag[]
     viewed:                 boolean
     related:                Post[]
-    createdAt:              string
     originalCreatedFrom:    string | null
-    originalCreatedBefore:  string | null }
+    originalCreatedBefore:  string | null
+    createdAt:              string
+    updatedAt:              string }
 
 export type PostTagChange = {
     post:       Post