diff --git a/app/controllers/work_item_controller.rb b/app/controllers/work_item_controller.rb
new file mode 100644
index 0000000..50b5930
--- /dev/null
+++ b/app/controllers/work_item_controller.rb
@@ -0,0 +1,15 @@
+class WorkItemController < ApplicationController
+  def start_time_entry
+    work_item = WorkItem.find(params[:id])
+
+    Toggl::start_time_entry(
+      description: work_item.title,
+      project_id: work_item.course.toggl_project,
+    )
+  end
+
+  def complete
+    work_item = WorkItem.find(params[:id])
+    work_item.complete!
+  end
+end
diff --git a/app/helpers/work_item_helper.rb b/app/helpers/work_item_helper.rb
new file mode 100644
index 0000000..bb332cb
--- /dev/null
+++ b/app/helpers/work_item_helper.rb
@@ -0,0 +1,2 @@
+module WorkItemHelper
+end
diff --git a/app/controllers/concerns/Trackable.rb b/app/models/concerns/Trackable.rb
similarity index 100%
rename from app/controllers/concerns/Trackable.rb
rename to app/models/concerns/Trackable.rb
diff --git a/app/models/concerns/course_item.rb b/app/models/concerns/course_item.rb
new file mode 100644
index 0000000..faf9cd2
--- /dev/null
+++ b/app/models/concerns/course_item.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module CourseItem
+  def week_number
+    ((start_time.beginning_of_week - course.semester_start_date.to_time) / 1.week).floor + 1
+  end
+end
diff --git a/app/models/lecture.rb b/app/models/lecture.rb
index e25b895..9333015 100644
--- a/app/models/lecture.rb
+++ b/app/models/lecture.rb
@@ -9,7 +9,7 @@ class Lecture < ApplicationRecord
     :problems_class,
   ], default: :lecture
 
-  include Trackable
+  include Trackable, CourseItem
 
   def prepared?
     tracked_time_entries.where(kind: [:preparation]).any?
@@ -35,10 +35,6 @@ class Lecture < ApplicationRecord
     tracked_time_entries.review.sum(&:duration).seconds
   end
 
-  def week_number
-    ((start_time.beginning_of_week - course.semester_start_date.to_time) / 1.week).floor + 1
-  end
-
   def live_video_url
     nil
   end
diff --git a/app/models/work_item.rb b/app/models/work_item.rb
index f63a20d..1e1f894 100644
--- a/app/models/work_item.rb
+++ b/app/models/work_item.rb
@@ -2,17 +2,38 @@ class WorkItem < ApplicationRecord
   belongs_to :course
   has_many :tracked_time_entries, dependent: :destroy, as: :subject
 
-  validate :due_date_after_start_date
+  validate :date_orderings
+  include Trackable, CourseItem
 
-  include Trackable
+  def start_time
+    available_from
+  end
 
-  def due_date_after_start_date
-    if due_date.present? && start_time.present? && due_date < start_time
-      errors.add(:due_date, "can't be before start date")
+  def completed?
+    completed_at.present?
+  end
+
+  def complete!
+    update(completed_at: Time.now)
+  end
+
+  def workable?
+    available_from.past? && !completed?
+  end
+
+  def started?
+    !tracked_time_entries.empty?
+  end
+
+  private
+
+  def date_orderings
+    if due_at.present? && available_from.present? && due_at < available_from
+      errors.add(:due_at, "can't be before date work item is available")
+    end
+
+    if completed_at.present? && available_from.present? && completed_at < available_from
+      errors.add(:completed_at, "can't be before date work item is available")
     end
   end
-
-  def week_number
-    ((start_time.beginning_of_week - course.semester_start_date.to_time) / 1.week).floor + 1
-  end
 end
diff --git a/app/views/work_item/complete.html.erb b/app/views/work_item/complete.html.erb
new file mode 100644
index 0000000..5fa51ca
--- /dev/null
+++ b/app/views/work_item/complete.html.erb
@@ -0,0 +1,4 @@
+<div>
+  <h1 class="font-bold text-4xl">WorkItem#complete</h1>
+  <p>Find me in app/views/work_item/complete.html.erb</p>
+</div>
diff --git a/app/views/work_item/start_time_entry.html.erb b/app/views/work_item/start_time_entry.html.erb
new file mode 100644
index 0000000..0db09d3
--- /dev/null
+++ b/app/views/work_item/start_time_entry.html.erb
@@ -0,0 +1,4 @@
+<div>
+  <h1 class="font-bold text-4xl">WorkItem#start_time_entry</h1>
+  <p>Find me in app/views/work_item/start_time_entry.html.erb</p>
+</div>
diff --git a/app/views/work_items/_work_item.html.erb b/app/views/work_items/_work_item.html.erb
index 7f3f98f..d65c76b 100644
--- a/app/views/work_items/_work_item.html.erb
+++ b/app/views/work_items/_work_item.html.erb
@@ -1,4 +1,8 @@
-<tr class="bg-purple-200">
+<tr class="<%= class_names({
+                             'lecture-future': work_item.available_from.future?,
+                             'bg-purple-200': work_item.workable?,
+                             'bg-green-100': work_item.completed?,
+                           }) %>">
   <td class="whitespace-nowrap py-4 pl-4 pr-3 text-sm font-medium text-gray-900 sm:pl-6">
     <%= work_item.title %>
   </td>
@@ -7,12 +11,19 @@
   </td>
 
   <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500" data-controller="popover" data-action="mouseenter->popover#show mouseleave->popover#hide">
-    <div class="flex flex-row gap-2">
-        <i class="fa fa-times text-red-700"></i>
+    <div class="flex flex-row gap-2 justify-center">
+      <% if work_item.completed? %>
+        <i class="fa fa-check text-green-700"></i>
+      <% elsif work_item.started? %>
+        <i class="fa fa-play text-blue-700"></i>
+      <% else %>
+        <%# Symbol to show work has not started yet %>
+        <i class="fa fa-clock text-blue-gray-700"></i>
+      <% end %>
     </div>
 
     <template data-popover-target="content">
-      <% unless work_item.tracked_time_entries.empty? %>
+      <% if work_item.started? %>
         <div class="absolute p-1 w-max whitespace-normal break-words rounded-lg border border-blue-gray-50 bg-white   text-blue-gray-500 shadow-lg shadow-blue-gray-500/10 focus:outline-none" data-popover-target="card">
           <div>
             Time spent: <%= humanise_duration(work_item.total_overall_time) %>
@@ -23,26 +34,25 @@
   </td>
 
   <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500">
-    <% if work_item.start_time.future? %>
-      <%= button_to "Prepare",
-                    "X",
+    <% if work_item.workable? %>
+      <% start_label = if work_item.started? then
+                         "Continue"
+                       else
+                         "Start"
+                       end %>
+      <%= button_to start_label,
+                    work_item_start_time_entry_path(work_item),
                     class: 'action-button'
       %>
-    <% elsif work_item.start_time.past? && work_item.due_date.future? %>
-      <%= button_to "Start",
-                    "X",
-                    class: 'action-button'
-      %>
-    <% else %>
-      <div class="flex justify-center">
-        <%= button_to "Review",
-                      "X",
-                      class: 'action-button'
-        %>
-      </div>
     <% end %>
   </td>
 
   <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500">
+    <% if work_item.started? && !work_item.completed? %>
+      <%= button_to "Complete",
+                    work_item_complete_path(work_item),
+                    class: 'action-button'
+      %>
+    <% end %>
   </td>
 </tr>
diff --git a/config/routes.rb b/config/routes.rb
index 8df9001..15695b9 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -15,5 +15,8 @@ Rails.application.routes.draw do
   post '/lectures/:id/start_preparation', to: 'lecture#start_preparation', as: :lecture_start_preparation
   post '/lectures/:id/start_review', to: 'lecture#start_review', as: :lecture_start_review
 
+  get '/work_items/:id/start_time_entry', to: 'work_item#start_time_entry', as: :work_item_start_time_entry
+  get '/work_items/:id/complete', to: 'work_item#complete', as: :work_item_complete
+
   post '/lectures/:id/checkin', to: 'lecture#checkin', as: :lecture_checkin
 end
diff --git a/db/migrate/20231008144635_rename_work_item_columns.rb b/db/migrate/20231008144635_rename_work_item_columns.rb
new file mode 100644
index 0000000..e7bb9f3
--- /dev/null
+++ b/db/migrate/20231008144635_rename_work_item_columns.rb
@@ -0,0 +1,6 @@
+class RenameWorkItemColumns < ActiveRecord::Migration[7.1]
+  def change
+    rename_column :work_items, :start_time, :available_from
+    rename_column :work_items, :due_date, :due_at
+  end
+end
diff --git a/db/migrate/20231008145328_add_completion_time_to_work_item.rb b/db/migrate/20231008145328_add_completion_time_to_work_item.rb
new file mode 100644
index 0000000..eb85ddc
--- /dev/null
+++ b/db/migrate/20231008145328_add_completion_time_to_work_item.rb
@@ -0,0 +1,5 @@
+class AddCompletionTimeToWorkItem < ActiveRecord::Migration[7.1]
+  def change
+    add_column :work_items, :completed_at, :datetime
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index ff9eceb..c21ee59 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2023_10_08_143146) do
+ActiveRecord::Schema[7.1].define(version: 2023_10_08_145328) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -64,10 +64,11 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_08_143146) do
   create_table "work_items", force: :cascade do |t|
     t.string "title", null: false
     t.bigint "course_id", null: false
-    t.datetime "due_date", null: false
+    t.datetime "due_at", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.datetime "start_time"
+    t.datetime "available_from"
+    t.datetime "completed_at"
     t.index ["course_id"], name: "index_work_items_on_course_id"
   end
 
diff --git a/test/controllers/work_item_controller_test.rb b/test/controllers/work_item_controller_test.rb
new file mode 100644
index 0000000..3dbec92
--- /dev/null
+++ b/test/controllers/work_item_controller_test.rb
@@ -0,0 +1,13 @@
+require "test_helper"
+
+class WorkItemControllerTest < ActionDispatch::IntegrationTest
+  test "should get start_time_entry" do
+    get work_item_start_time_entry_url
+    assert_response :success
+  end
+
+  test "should get complete" do
+    get work_item_complete_url
+    assert_response :success
+  end
+end