Use `started` key to show the triggered date

app/assets/javascripts/jobs/components/header.vue

@@ -42,6 +42,9 @@ export default {
     jobStarted() {
       return !this.job.started === false;
     },
+    headerTime() {
+      return this.jobStarted ? this.job.started : this.job.created_at;
+    },
   },
   watch: {
     job() {
@@ -73,7 +76,7 @@ export default {
         :status="status"
         item-name="Job"
         :item-id="job.id"
-        :time="job.created_at"
+        :time="headerTime"
         :user="job.user"
         :actions="actions"
         :has-sidebar-button="true"

spec/javascripts/jobs/header_spec.js

@@ -13,6 +13,9 @@ describe('Job details header', () => {
     const threeWeeksAgo = new Date();
     threeWeeksAgo.setDate(threeWeeksAgo.getDate() - 21);
 
+    const twoDaysAgo = new Date();
+    twoDaysAgo.setDate(twoDaysAgo.getDate() - 2);
+
     props = {
       job: {
         status: {
@@ -31,7 +34,7 @@ describe('Job details header', () => {
           email: 'foo@bar.com',
           avatar_url: 'link',
         },
-        started: '2018-01-08T09:48:27.319Z',
+        started: twoDaysAgo.toISOString(),
         new_issue_path: 'path',
       },
       isLoading: false,
@@ -69,7 +72,7 @@ describe('Job details header', () => {
           .querySelector('.header-main-content')
           .textContent.replace(/\s+/g, ' ')
           .trim(),
-      ).toEqual('failed Job #123 triggered 3 weeks ago by Foo');
+      ).toEqual('failed Job #123 triggered 2 days ago by Foo');
     });
 
     it('should render new issue link', () => {