diff --git a/app/assets/javascripts/discourse/controllers/change-timestamp.js.es6 b/app/assets/javascripts/discourse/controllers/change-timestamp.js.es6
new file mode 100644
index 000000000..1d55e74cf
--- /dev/null
+++ b/app/assets/javascripts/discourse/controllers/change-timestamp.js.es6
@@ -0,0 +1,58 @@
+import ModalFunctionality from 'discourse/mixins/modal-functionality';
+import computed from 'ember-addons/ember-computed-decorators';
+
+// Modal related to changing the timestamp of posts
+export default Ember.Controller.extend(ModalFunctionality, {
+  needs: ['topic'],
+
+  topicController: Em.computed.alias('controllers.topic'),
+  saving: false,
+  date: '',
+  time: '',
+
+  @computed('saving')
+  buttonTitle(saving) {
+    return saving ? I18n.t('saving') : I18n.t('topic.change_timestamp.action');
+  },
+
+  @computed('date', 'time')
+  createdAt(date, time) {
+    return moment(date + ' ' + time, 'YYYY-MM-DD HH:mm:ss');
+  },
+
+  @computed('createdAt')
+  validTimestamp(createdAt) {
+    return moment().diff(createdAt, 'minutes') < 0;
+  },
+
+  @computed('saving', 'date', 'validTimestamp')
+  buttonDisabled() {
+    if (this.get('saving') || this.get('validTimestamp')) return true;
+    return Ember.isEmpty(this.get('date'));
+  },
+
+  onShow: function() {
+    this.setProperties({
+      date: moment().format('YYYY-MM-DD')
+    });
+  },
+
+  actions: {
+    changeTimestamp: function() {
+      this.set('saving', true);
+      const self = this;
+
+      Discourse.Topic.changeTimestamp(
+        this.get('topicController.model.id'),
+        this.get('createdAt').unix()
+      ).then(function() {
+        self.send('closeModal');
+        self.setProperties({ date: '', time: '', saving: false });
+      }).catch(function() {
+        self.flash(I18n.t('topic.change_timestamp.error'), 'alert-error');
+        self.set('saving', false);
+      });
+      return false;
+    }
+  }
+});
diff --git a/app/assets/javascripts/discourse/models/topic.js.es6 b/app/assets/javascripts/discourse/models/topic.js.es6
index 073784934..88d99fa3b 100644
--- a/app/assets/javascripts/discourse/models/topic.js.es6
+++ b/app/assets/javascripts/discourse/models/topic.js.es6
@@ -480,6 +480,17 @@ Topic.reopenClass({
     return promise;
   },
 
+  changeTimestamp(topicId, timestamp) {
+    const promise = Discourse.ajax("/t/" + topicId + '/change-timestamp', {
+      type: 'PUT',
+      data: { timestamp: timestamp },
+    }).then(function(result) {
+      if (result.success) return result;
+      promise.reject(new Error("error updating timestamp of topic"));
+    });
+    return promise;
+  },
+
   bulkOperation(topics, operation) {
     return Discourse.ajax("/topics/bulk", {
       type: 'PUT',
diff --git a/app/assets/javascripts/discourse/routes/topic.js.es6 b/app/assets/javascripts/discourse/routes/topic.js.es6
index c79ccbe5c..04d3ae202 100644
--- a/app/assets/javascripts/discourse/routes/topic.js.es6
+++ b/app/assets/javascripts/discourse/routes/topic.js.es6
@@ -60,6 +60,10 @@ const TopicRoute = Discourse.Route.extend({
       this.controllerFor('modal').set('modalClass', 'edit-auto-close-modal');
     },
 
+    showChangeTimestamp() {
+      showModal('change-timestamp', { model: this.modelFor('topic'), title: 'topic.change_timestamp.title' });
+    },
+
     showFeatureTopic() {
       showModal('featureTopic', { model: this.modelFor('topic'), title: 'topic.feature_topic.title' });
       this.controllerFor('modal').set('modalClass', 'feature-topic-modal');
diff --git a/app/assets/javascripts/discourse/templates/modal/change-timestamp.hbs b/app/assets/javascripts/discourse/templates/modal/change-timestamp.hbs
new file mode 100644
index 000000000..c76c58e12
--- /dev/null
+++ b/app/assets/javascripts/discourse/templates/modal/change-timestamp.hbs
@@ -0,0 +1,18 @@
+<div class="modal-body">
+  <p>
+    {{i18n 'topic.change_timestamp.instructions'}}
+  </p>
+
+  <p {{bind-attr class=":alert :alert-error validTimestamp::hidden"}}>
+    {{i18n 'topic.change_timestamp.invalid_timestamp'}}
+  </p>
+
+  <form>
+    {{input type="date" value=date}}
+    {{input type="time" value=time}}
+  </form>
+</div>
+
+<div class="modal-footer">
+  <button class="btn btn-primary" {{bind-attr disabled="buttonDisabled"}} {{action "changeTimestamp"}}>{{buttonTitle}}</button>
+</div>
diff --git a/app/assets/javascripts/discourse/templates/topic-admin-menu.hbs b/app/assets/javascripts/discourse/templates/topic-admin-menu.hbs
index 004df5255..2f190df21 100644
--- a/app/assets/javascripts/discourse/templates/topic-admin-menu.hbs
+++ b/app/assets/javascripts/discourse/templates/topic-admin-menu.hbs
@@ -38,6 +38,10 @@
     {{/if}}
   {{/unless}}
 
+  <li>
+    {{d-button action="showChangeTimestamp" icon="calendar" label="topic.change_timestamp.title" class="btn-admin"}}
+  </li>
+
   <li>
     {{#if model.archived}}
       {{d-button action="toggleArchived" icon="folder" label="topic.actions.unarchive" class="btn-admin"}}
diff --git a/app/controllers/topics_controller.rb b/app/controllers/topics_controller.rb
index 01d960e54..f728f35c6 100644
--- a/app/controllers/topics_controller.rb
+++ b/app/controllers/topics_controller.rb
@@ -24,6 +24,7 @@ class TopicsController < ApplicationController
                                           :bulk,
                                           :reset_new,
                                           :change_post_owners,
+                                          :change_timestamps,
                                           :bookmark,
                                           :unsubscribe]
 
@@ -375,6 +376,22 @@ class TopicsController < ApplicationController
     end
   end
 
+  def change_timestamps
+    params.require(:topic_id)
+    params.require(:timestamp)
+
+    guardian.ensure_can_change_post_owner!
+
+    begin
+      PostTimestampChanger.new( topic_id: params[:topic_id].to_i,
+                                timestamp: params[:timestamp].to_i ).change!
+
+      render json: success_json
+    rescue ActiveRecord::RecordInvalid
+      render json: failed_json, status: 422
+    end
+  end
+
   def clear_pin
     topic = Topic.find_by(id: params[:topic_id].to_i)
     guardian.ensure_can_see!(topic)
diff --git a/app/services/post_timestamp_changer.rb b/app/services/post_timestamp_changer.rb
new file mode 100644
index 000000000..65b056128
--- /dev/null
+++ b/app/services/post_timestamp_changer.rb
@@ -0,0 +1,43 @@
+class PostTimestampChanger
+  def initialize(params)
+    @topic = Topic.with_deleted.find(params[:topic_id])
+    @posts = @topic.posts
+    @timestamp = Time.at(params[:timestamp])
+    @time_difference = calculate_time_difference
+  end
+
+  def change!
+    ActiveRecord::Base.transaction do
+      update_topic
+
+      @posts.each do |post|
+        if post.is_first_post?
+          update_post(post, @timestamp)
+        else
+          update_post(post, Time.at(post.created_at.to_f + @time_difference))
+        end
+      end
+    end
+
+    # Burst the cache for stats
+    [AdminDashboardData, About].each { |klass| $redis.del klass.stats_cache_key }
+  end
+
+  private
+
+  def calculate_time_difference
+    @timestamp - @topic.created_at
+  end
+
+  def update_topic
+    @topic.update_attributes(
+      created_at: @timestamp,
+      updated_at: @timestamp,
+      bumped_at: @timestamp
+    )
+  end
+
+  def update_post(post, timestamp)
+    post.update_attributes(created_at: timestamp, updated_at: timestamp)
+  end
+end
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 520b881c7..d85e2a46d 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -1241,6 +1241,13 @@ en:
           other: "Please choose the new owner of the {{count}} posts by <b>{{old_user}}</b>."
         instructions_warn: "Note that any notifications about this post will not be transferred to the new user retroactively.<br>Warning: Currently, no post-dependent data is transferred over to the new user. Use with caution."
 
+      change_timestamp:
+        title: "Change Timestamp"
+        action: "change timestamp"
+        invalid_timestamp: "Timestamp cannot be in the future."
+        error: "There was an error changing the timestamp of the topic."
+        instructions: "Please select the new timestamp of the topic. Posts in the topic will be updated to have the same time difference."
+
       multi_select:
         select: 'select'
         selected: 'selected ({{count}})'
diff --git a/config/routes.rb b/config/routes.rb
index 9b0e6cc40..235f82432 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -469,6 +469,7 @@ Discourse::Application.routes.draw do
   post "t/:topic_id/move-posts" => "topics#move_posts", constraints: {topic_id: /\d+/}
   post "t/:topic_id/merge-topic" => "topics#merge_topic", constraints: {topic_id: /\d+/}
   post "t/:topic_id/change-owner" => "topics#change_post_owners", constraints: {topic_id: /\d+/}
+  put "t/:topic_id/change-timestamp" => "topics#change_timestamps", constraints: {topic_id: /\d+/}
   delete "t/:topic_id/timings" => "topics#destroy_timings", constraints: {topic_id: /\d+/}
   put "t/:topic_id/bookmark" => "topics#bookmark", constraints: {topic_id: /\d+/}
   put "t/:topic_id/remove_bookmarks" => "topics#remove_bookmarks", constraints: {topic_id: /\d+/}
diff --git a/spec/controllers/topics_controller_spec.rb b/spec/controllers/topics_controller_spec.rb
index 8994e5de9..8b31305ee 100644
--- a/spec/controllers/topics_controller_spec.rb
+++ b/spec/controllers/topics_controller_spec.rb
@@ -263,6 +263,45 @@ describe TopicsController do
     end
   end
 
+  context 'change_timestamps' do
+    let(:params) { { topic_id: 1, timestamp: Time.zone.now } }
+
+    it 'needs you to be logged in' do
+      expect { xhr :put, :change_timestamps, params }.to raise_error(Discourse::NotLoggedIn)
+    end
+
+    [:moderator, :trust_level_4].each do |user|
+      describe "forbidden to #{user}" do
+        let!(user) { log_in(user) }
+
+        it 'correctly denies' do
+          xhr :put, :change_timestamps, params
+          expect(response).to be_forbidden
+        end
+      end
+    end
+
+    describe 'changing timestamps' do
+      let!(:admin) { log_in(:admin) }
+      let(:old_timestamp) { Time.zone.now }
+      let(:new_timestamp) { old_timestamp - 1.day }
+      let!(:topic) { Fabricate(:topic, created_at: old_timestamp) }
+      let!(:p1) { Fabricate(:post, topic_id: topic.id, created_at: old_timestamp) }
+      let!(:p2) { Fabricate(:post, topic_id: topic.id, created_at: old_timestamp + 1.day) }
+
+      it 'raises an error with a missing parameter' do
+        expect { xhr :put, :change_timestamps, topic_id: 1 }.to raise_error(ActionController::ParameterMissing)
+      end
+
+      it 'should update the timestamps of selected posts' do
+        xhr :put, :change_timestamps, topic_id: topic.id, timestamp: new_timestamp.to_f
+        expect(topic.reload.created_at.to_s).to eq(new_timestamp.to_s)
+        expect(p1.reload.created_at.to_s).to eq(new_timestamp.to_s)
+        expect(p2.reload.created_at.to_s).to eq(old_timestamp.to_s)
+      end
+    end
+  end
+
   context 'clear_pin' do
     it 'needs you to be logged in' do
       expect { xhr :put, :clear_pin, topic_id: 1 }.to raise_error(Discourse::NotLoggedIn)
diff --git a/spec/services/post_timestamp_changer_spec.rb b/spec/services/post_timestamp_changer_spec.rb
new file mode 100644
index 000000000..506459687
--- /dev/null
+++ b/spec/services/post_timestamp_changer_spec.rb
@@ -0,0 +1,55 @@
+require 'spec_helper'
+
+describe PostTimestampChanger do
+  describe "change!" do
+    let(:old_timestamp) { Time.zone.now }
+    let(:new_timestamp) { old_timestamp + 1.day }
+    let!(:topic) { Fabricate(:topic, created_at: old_timestamp) }
+    let!(:p1) { Fabricate(:post, topic: topic, created_at: old_timestamp) }
+    let!(:p2) { Fabricate(:post, topic: topic, created_at: old_timestamp + 1.day) }
+    let(:params) { { topic_id: topic.id, timestamp: new_timestamp.to_f } }
+
+    it 'changes the timestamp of the topic and opening post' do
+      PostTimestampChanger.new(params).change!
+
+      topic.reload
+      [:created_at, :updated_at, :bumped_at].each do |column|
+        expect(topic.public_send(column).to_s).to eq(new_timestamp.to_s)
+      end
+
+      p1.reload
+      [:created_at, :updated_at].each do |column|
+        expect(p1.public_send(column).to_s).to eq(new_timestamp.to_s)
+      end
+    end
+
+    describe 'predated timestamp' do
+      it 'updates the timestamp of posts in the topic with the time difference applied' do
+        PostTimestampChanger.new(params).change!
+
+        p2.reload
+        [:created_at, :updated_at].each do |column|
+          expect(p2.public_send(column).to_s).to eq((old_timestamp + 2.day).to_s)
+        end
+      end
+    end
+
+    describe 'backdated timestamp' do
+      let(:new_timestamp) { old_timestamp - 1.day }
+
+      it 'updates the timestamp of posts in the topic with the time difference applied' do
+        PostTimestampChanger.new(params).change!
+
+        p2.reload
+        [:created_at, :updated_at].each do |column|
+          expect(p2.public_send(column).to_s).to eq((old_timestamp).to_s)
+        end
+      end
+    end
+
+    it 'deletes the stats cache' do
+      $redis.expects(:del).twice
+      PostTimestampChanger.new(params).change!
+    end
+  end
+end