use an empty total time when the build has not started yet so the UI knows

app/serializers/analytics_build_entity.rb

@@ -13,7 +13,7 @@ class AnalyticsBuildEntity < Grape::Entity
   end
 
   expose :duration, as: :total_time do |build|
-    distance_of_time_as_hash(build.duration.to_f)
+    build_started?(build) ? distance_of_time_as_hash(build.duration.to_f) : {}
   end
 
   expose :branch do
@@ -37,4 +37,8 @@ class AnalyticsBuildEntity < Grape::Entity
   def url_to(route, build, id = nil)
     public_send("#{route}_url", build.project.namespace, build.project, id || build)
   end
+
+  def build_started?(build)
+    build.duration && build[:started_at]
+  end
 end

app/serializers/entity_date_helper.rb

@@ -2,7 +2,7 @@ module EntityDateHelper
   include ActionView::Helpers::DateHelper
 
   def interval_in_words(diff)
-    return 'not started' unless diff
+    return 'Not started' unless diff
 
     "#{distance_of_time_in_words(Time.now, diff)} ago"
   end

spec/serializers/analytics_build_entity_spec.rb

@@ -42,7 +42,13 @@ describe AnalyticsBuildEntity do
         expect{ subject[:date] }.not_to raise_error
       end
 
-      it ''
+      it 'shows the right message' do
+        expect(subject[:date]).to eq('Not started')
+      end
+
+      it 'shows the right total time' do
+        expect(subject[:total_time]).to eq({})
+      end
     end
 
     context 'no started at date' do
@@ -51,6 +57,14 @@ describe AnalyticsBuildEntity do
       it 'does not blow up' do
         expect{ subject[:date] }.not_to raise_error
       end
+
+      it 'shows the right message' do
+        expect(subject[:date]).to eq('Not started')
+      end
+
+      it 'shows the right total time' do
+        expect(subject[:total_time]).to eq({})
+      end
     end
 
     context 'no finished at date' do
@@ -59,6 +73,14 @@ describe AnalyticsBuildEntity do
       it 'does not blow up' do
         expect{ subject[:date] }.not_to raise_error
       end
+
+      it 'shows the right message' do
+        expect(subject[:date]).to eq('about 2 hours ago')
+      end
+
+      it 'shows the right total time' do
+        expect(subject[:total_time]).to eq({hours: 2})
+      end
     end
   end
 end